- "I will announce the goal for everyone turn Ainz Ooal Gown into an eternal legend. If there are many heroes, then we will replace them all. Let the entire world know that Ainz Ooal Gown is the true hero!"
- - Ainz announcing his goals, setting all of Nazarick into motion
Ainz Ooal Gown (アインズ・ウール・ゴウン), formerly known as Momonga (モモンガ), is the main protagonist of the Overlord series. He is the guild master of Ainz Ooal Gown, Overlord of the Great Tomb of Nazarick and the creator of Pandora's Actor. He is regarded as the highest of the Almighty Forty-One Supreme Beings by the NPCs of Nazarick.
In the New World, he is the Sorcerer King of the Sorcerer Kingdom and the most powerful magic caster in the world. His other identity is famously known as "Momon," a dark warrior and leader of Darkness, an adamantite ranked adventurer group of that nation. He is an adamantite class adventurer and the strongest adventurer known in E-Rantel.
Ainz Ooal Gown has the appearance of an Overlord, an undead skeleton creature who is devoid of skin and flesh. He tends to mainly wear an elaborate, jet-black academic gown adorned with golden and violet edges. When he had no clothes on, his whole body alone is purely made up of just his bones. He also has a dark red orb floating under his ribs that emanate a feeling of dread.
Furthermore, he has a type of tiny dark red glow radiating from inside his empty eye sockets. Sometimes, however, that glow can become largely intensified, leading it to elicit faint reddish flames flickering about in both his two eyes. Additionally, Ainz has a dark halo-like object glimmering right behind his head.
In his dark warrior persona as Momon, Ainz would wear a fully jet-black body armor adorned with purple and golden markings. Not only that, but he has on a red cape out of admiration for Touch Me. He is equipped with two large swords on his back while carrying it behind him.
While Ainz is a cautious and stingy person, he would always try to plan ahead and control details beforehand in order to avoid any haphazard actions that can endanger Nazarick's existence. This means going so far as lying to the inhabitants in the New World that he can't used one of his Super-tier spells for years to come after using it once. Since being transferred to a new world and becoming an actual undead being, Ainz could feel himself becoming very cold and calculating while his emotions repressed.
As the guildmaster of Ainz Ooal Gown, he loves to reminisce about the wise words from his fellow guildmates as they may hold some meaning now in the new world, which the NPCs wholeheartedly agreed too. As he is loyal to his friends and the NPCs created by them, he then acts with a certain degree of nobility, when leading his devoted followers properly, seeing him in the image of a divine entity. It was so they can faithfully have a Supreme Being to look up to and depend on since he is the ruler of the Great Tomb of Nazarick and the last Supreme Being to have stay with them even after their creators have left them behind. He is caring for them like a father figure would as Ainz tries to act that way for Pandora's Actor and his friends' NPCs.
When he was crowned king of his newly-formed country the Sorcerer Kingdom, this trait also plays a certain key role in earning loyalties among his countrymen. For instance, the Guildmaster Ainzach describes Ainz as being a rational person who makes wise decisions carefully, commanding him to be an intellectual, but merciful ruler. Additionally, Ainz is open-minded to others' opinions of the actions he has partaken, appreciating their criticisms and learning from his mistakes, in which the Floor Guardians couldn't do to help him.
Furthermore, Ainz is not only looking upon as a thoughtful and generous person but also by the people who work for him while kindly rewarding them with YGGDRASIL items due to their hard work. At the same time, Ainz is true to his words and oath, when he honorably accepted certain conditions made by individuals in the form of promises held to a high degree without betraying them. He has a benevolent nature of ruling over his nation peacefully without bloodshed, figuring there is still always room for reasonable negotiation. Yet at times, however, Ainz would feel paranoid and pessimistic that his Floor Guardians or other NPCs that follow after them may someday abandon him if he doesn't live up to their expectations.
Nonetheless, he only does things that will benefit Nazarick or himself above all else, whether its information or prestige. Although he does have a sense of justice and doesn't hate humans as much as his followers, Ainz holds no deep attachment to them, and he feels nothing toward their deaths. Ainz did not view humanity as an enemy, but he could kill human beings with no hesitation for the sake of his goals. Even so, he wanted to avoid conflict with other players especially the ones who are human that would protect their kind. After killing Shalltear with his own hands, he became a lot more vigilant and hostile against players or other foes with World Items that could possibly harm Nazarick in the near future. Aside from the NPCs of Nazarick, the only players Ainz will show most concerned for were his past companions.
On the other hand, Ainz has a competitive side to him, regarding the actions of players within the new world was what motivated him to not fall behind in terms of technological development. Likewise, everything he does was all for the sake of Ainz Ooal Gown, the Great Tomb of Nazarick, and the Sorcerer Kingdom altogether. For that reason, Ainz is secretive about the information he may have gained, refusing to disclose anything in case it serves Nazarick's interest. Since Ainz prioritizes knowledge as an utmost importance to him, he also likes to participate in doing random experiments. With the sole purpose of obtaining valuable information on the New World's inhabitants, martial arts, magic, items, or even their way of life such as religion.
In his dark warrior persona as Momon, he is viewed by people to be very dignified as a worthy adamantite adventurer yet not willing to make others uncomfortable around him. True to his nature, Momon is also very faithful and honorable, when he refused Nfirea's request for the Swords of Darkness, prioritizing them first as it was something he accepted before anything else. While he holds great trust with his comrades, he refuses outside aid if they happen to slow him down during his job. Let alone that, he would use some of his spare time to exchange greetings with every single adventurer's group in the Re-Estize Kingdom. Out of respect for his fellow adventurers, he doesn't like to reap the rewards for himself and wants them who took part in stopping the disturbance within Re-Estize to be paid equally as well.
In the Real World
In the year of 2138 before taking on the name of Ainz Ooal Gown in the new world, Momonga was his original name as a player in YGGDRASIL. But in reality, he was a human being by the name of Suzuki Satoru, his true identity. Whenever Suzuki left home while heading to his workplace, he wears an air filtering mask and goggles to prevent himself from being affected by the toxic air outside. Somewhere during his lifetime, Suzuki lost his mother due to fatigue as she overworked herself to death. Her death occurred in the kitchen of Suzuki's home, where she collapsed on the floor. She was pushing herself to make his favorite dish before this horrific event took place. He vividly remembers seeing it happen with his own eyes in the morning upon waking up.
On the other hand, Suzuki Satoru is a elementary school graduate and salaryman who lives alone in a broken-down apartment. Because Momonga does not have any real family or friends to support him, he dedicated his whole life instead to the DMMO-RPG, YGGDRASIL and just his guild. His life was an endless cycle of going to the office to work. Memories of the time he spent with his friends as members of Ainz Ooal Gown were all he had in the game. Momonga's daily livelihood to the game has even gone so far to the extent, where he used up most of the money financially obtain by him from work. His salary earnings were meager, but he still lived above the poverty line. Momonga had an ample balance in his bank accounts, yet he had no idea how to spend that money. In the end, it was apparent that Momonga has already spent almost one-third of his monthly salary on cash purchases for the game.
Nine's Own Goal
When Momonga first began playing YGGDRASIL, the idea of killing Heteromorphic Races is a common practice in YGGDRASIL. At that time, he was one of the targets who was hunted down and killed by PKers multiple times. Having enough of the harsh treatment, he was very close to quitting the game until Touch Me's words had saved him.
In the anime, he is shown to be surrounded by a group of PKers in their attempt to finish him off while mocking his character avatar. However, as they were about to carry out the PK on Momonga, Touch Me suddenly came to his rescue and defeated them simultaneously. Since then, both Momonga and Touch Me made friends with seven others like them together to form the First Nine, which started out as a PvP/PKer clan, known as the Nine's Own Goal.
At some point in time, during a meeting with his clansmen, Touch Me thought of disbanding the Nine's Own Goal and wanted to form a guild and recommending Momonga to be their leader. Once the clan is dissolved and the members present agreed to accept Momonga as the guild master, he and friends created the official guild called Ainz Ooal Gown. Carrying out the role as the Guildmaster of Ainz Ooal Gown, Momonga is now tasked with the miscellaneous work such as contacting people in the guild from this moment forward.
Guild Master of Ainz Ooal Gown
Right after the guild was created, Momonga would lead Ainz Ooal Gown and its members to an unknown dungeon called the Great Tomb of Nazarick thanks to the efforts of his friend, Nishikienrai for locating it. Due to Momonga's leadership and cooperation with his guild members, it led to the guild being able to conquer the Great Tomb of Nazarick and shortly afterward, also acquiring a World Item called the Throne of Kings the same moment they cleared the dungeon. The dungeon would later serve to be Ainz Ooal Gown's future guild base while dealing with the invasion of players intruding on their location.
On the other hand, there were other players who started to perceive the guild of heteromorphic races as evil beings that must be defeated at all costs. Hence, the guild members of Ainz Ooal Gown including Momonga thought that it was only proper for them to become real monsters. It was indicated during the players' invasion of their guild base that Ulbert suggesting they should also act as final bosses unless the enemies are able to reach them.
During those years, Momonga and his guildmates spent most of their work and effort focused on building their guild weapon known as the Staff of Ainz Ooal Gown. In addition to that, Momonga and his guildmates created their own customized NPCs, which for him was Pandora's Actor. He made Pandora's Actor to not only preserve the identity of Ainz Ooal Gown but to serve in protecting the guild's treasury for starters. At some point in time, however, nearly 37 out of his 41 guildmates quit the game altogether, leaving the guild and giving away their player's equipment to Momonga. Not just quit the game, but as well as deleting their character's avatar completely due to real-world issues his guild members had to deal with. He would later store most of his guild members' equipment into the Treasury for safekeeping. Momonga also made all of the Avataras in the image of his guildmates, who quit the game.
Prior to them leaving the guild and YGGDRASIL, Momonga would return straight home after work every day, log onto the DMMO-RPG ahead of everyone else. It is something he does during the era when the guild was still actively thriving with plenty of members online. There, he will also begin making preparations in Nazarick before his comrades go online. He would summon numerous undead to protect himself as well as hiring NPC mercenaries to hunt down monsters with the guild's goal in funding Nazarick. Extremely dedicated to the game, he was used to playing on his own most of the time when they are offline or inactive in YGGDRASIL.
Since most of his guild members have already quit the DMMO-RPG, Momonga continued to stay behind and kept their guild base running. He had begun solo hunting areas and farming for things by himself to a nearly ridiculous degree to earn the gold needed to maintain the Great Tomb of Nazarick. The dungeon seems to be on top notch shape according to Herohero as he apparently taken notice of Momonga's efforts done to manage it as their guildmaster. Herohero believes that Momonga's devotion to maintaining the dungeon for this long was in hopes that they will one day return to the game and play with him again. Because of that, he did not bother to build new friendships with other players and avoided them, as well as the high-difficulty areas he used to visit when his guild members had still been around. Then, he would deposit his earnings in the Treasury before logging out. This had been his routine for almost daily. As such, he did not have much contact with some of the NPCs and hardly knew a thing about them until now.
Nonetheless, the tedious labor Momonga has spent while maintaining their guild base financially have managed to paid off as no players were still unable to conquer the Great Tomb of Nazarick even after the game's shutdown. This also applies to the number of times and efforts he put forward into the game to prevent the guild's rank being formerly 9th from dropping any further than 29th as its current ranking. Strength-wise, Momonga did it all on his own as he was the only manpower who happen to be active daily within the guild.
The Undead King Arc
- Main article: The Undead King Arc
Momonga, the guildmaster of Ainz Ooal Gown, is conversing together with Herohero during the last moments of YGGDRASIL before shutdown. Herohero bid farewell to Momonga and logs out for the last time as he has already quit the game. Mentally, Momonga is enraged about his friends leaving the game, but cools down after noting that they didn't abandon the guild - it was that they had real life issues to deal with. Still engrossed in the memories of the past, he takes the Staff of Ainz Ooal Gown before heading to the throne room.
Once there, Momonga encounters Sebas Tian and Pleiades at the Royal Suite and calls for them to accompany him. At the throne room, he discovers Albedo holding a World Item. While he is initially irritated that her creator Tabula Smaragdina broke the guild rules, he quickly forgives him since Albedo was one of his treasured creations. Momonga looks through her settings and reprograms her to be in love with him. With little time left, he sits on the throne and points at the banners, calling out the names of his guild members while waiting for the server to shut down. Unexpectedly, the server does not shut down and Momonga quickly realizes that something is wrong when the NPCs begin talking. Staying calm, he orders Sebas to survey the surrounding area on the surface and orders Albedo to assemble the Floor Guardians on the 6th Floor. Brooding to himself, he concludes that all of the NPCs have gained sentience and agonizes over Albedo's modified settings.
Later on, Momonga goes to the Amphitheater on the 6th Floor and meets with Aura and Mare. He asks the two that he is testing the Staff of Ainz Ooal Gown. After the experiment, he summons the Primal Fire Elemental and asks Aura if she wants to fight it which Aura agrees, dragging Mare along. When they finish the fight, the Floor Guardians start gathering one by one until everyone is fully assembled together and pledge their absolute loyalty to Momonga. Upon confirming their loyalty, Momonga goes back to the Throne. 
While so, Demiurge, who spots Momonga trying to leave the area, requests him to allow him to be his escort outside of Nazarick to see the New World. After seeing the new world, he goes to Mare and rewards him the Ring of Ainz Ooal Gown for doing a splendid job. He also gives a ring to Albedo and then teleports back to Nazarick. Momonga using Mirror of Remote Viewing discovers a village being attacked by knights. At first, Ainz doesn't want to get involved in the conflict, but when reminiscing about Touch Me, who had once saved his life, however, he decides to save the village. He then teleports to the outskirt of the village and saves Enri Emmot and Nemu Emmot, who is being chased by the knights.  After saving them, he summons a Death Knight and orders it to kill the knights attacking the village. He saves Carne Village and gathers information about the New World from the village chief. He decides to withdraw but is soon confronted by Gazef Stronoff and his warrior troop's arrival at the village. He introduces himself as Ainz Ooal Gown who save the village from the knights. After he is thanked by Gazef, his subordinate informs him that the village is surrounded by unknown figures.
Hence, Ainz also comes across these unknown figures who have Archangel Flame with them similar that of YGGDRASIL monsters. He realizes that Gazef is their target and he gives him a sculpture for good luck in his battle.  All of a sudden, he magically switches places with Gazef due to that item's power and faces the Sunlight Scripture led by Nigun Grid Luin in his stead. Ainz offers them the chance to surrender to their lives or face death. He uses Negative Burst on the Archangel Flame, then uses Hell Flame on the Principality Observation and finally uses his Black Hole to finish off the Dominion Authority. He easily defeats the Sunlight Scripture and goes back to Carne Village to check Gazef's condition before leaving the village. After returning to Nazarick, he announces to his NPCs that he will no longer go by the name of Momonga, but calling himself Ainz Ooal Gown from now on, ordering them to make his new name an eternal legend to the New World. 
The Dark Warrior Arc
- Main article: The Dark Warrior Arc
Ainz Ooal Gown alongside Narberal Gamma goes undercover as adventurers under the alias of Momon and Nabe. They infiltrate the fortress city of E-Rantel and register as copper class adventurers. Along the way, they caused a commotion at the inn which led Momon to give Brita a potion for compensation. He discusses his plan to Nabe about their objective in this city. He plans on becoming famous adventurers and gathers information about this world. They went to the Adventurer's Guild to search for a job and the group ended up meeting Swords of Darkness, who offer him and Nabe a job. After the discussion, the female receptionist informs Momon that someone else requested him for a specific job. As a result, he meets Nfirea Bareare, who requested Momon to be his escort to Carne Village while gathering herbs along the way. Nevertheless, Momon accepts both of their requests and their journey begins. 
As they travel to Carne Village, the party is attacked by a large group of goblins and ogres. A battle plan is formulated quickly, whereas the Swords of Darkness is in-charge of fighting the goblins, Momon and Nabe deal with eliminating the ogres. As the fight proceeds, Momon kills the ogres while Nabe finishes off the rest. The journey proceeds smoothly after the encounter, but things are amiss as Carne Village is more fortified than usual. Sensing that something is wrong, the party advances cautiously but is ambushed by the Goblin Troop. Momon realizes that the goblins are in fact, Enri's summons through the use of the Horn of the Goblin General for the sake of protecting the village. 
Later on, Momon's true identity as Ainz Ooal Gown is eventually discovered by Nfirea. This is due to the clues Ainz left behind in E-Rantel, which the Nfirea was able to somehow piece together to help him realize who Ainz really is behind the adventurer persona. Thus, he apologized to Ainz for deceiving him and wanted to thank him for saving Enri and Carne Village. Nfirea also tells Ainz, that the request was just his attempt to learn more about Ainz's rare potion. After convincing Nfirea not to reveal his identity any further, they went to the forest to gather some herbs. Ainz orders Aura to lure out the Wise King of the Forest to him, so he can challenge him in battle. Upon fighting it, however, he was disappointed that the Wise King of the Forest is actually a giant hamster all along and tamed it easily. Momon then showed it to the Swords of Darkness that he has the Wise King of the Forest under his control. 
They return back to E-Rantel, where Momon goes to the Adventurer's Guild, so he can register Hamsuke as his mount and pet. Once Momon finishes Hamsuke's registration, he met up with Lizzie Bareare, grandmother of Nfirea, who led them to her workshop. He discovers that the Swords of Darkness are killed and turned into a zombie. As a result, Momon was immediately left with no other choice, but to kill them, and begin investigating what had transpired while he was away. Momon finds out that Nfirea was kidnapped and tells Lizzie to hire him so that he can save Nfirea. They went to the cemetery and breakthrough the mob of undead and confronted the two instigators. He then has a one on one duel with Clementine and won successfully, finishing her off with a bear hug which led to her own death. After resolving the incident, he leaves behind the enemy's corpses to the authorities as proof that they were the instigators. With the mess settled, Momon and Nabe are quickly promoted to Mythril class adventurers.  They returned back to the inn and discuss what to do with Nfirea and Lizzie. Suddenly, Ainz is informed by Albedo that Shalltear Bloodfallen has rebelled. 
The Bloody Valkyrie Arc
- Main article: The Bloody Valkyrie Arc
After being informed by Albedo that Shalltear Bloodfallen has rebelled, Ainz returns back to Nazarick and tries to figure out why the vampire has gone rogue. He and Albedo went to the 5th Floor to visit Nigredo and used her to find Shalltear. They discover that Shalltear is now fully equipped in her Bloody Valkyrie form. However, Ainz is informed by Narberal that the Adventurer's Guild at E-Rantel is looking for him. He then went to the Adventurer's Guild meeting and discuss a powerful vampire. Momon convinces and insists to the Guild leaders, E-Rantel's authorities and his fellow Mythril adventurers that he will exterminate the vampire in sight. When the meeting is over, he went to the forest and orders Albedo and Mare to dispose of Kralgra, who ignored his advice and chose to follow.
Later, he finds Shalltear and used Wish Upon a Star, a super-tier spell which failed to get rid of her mind-control. As a result, he assumes the worst from this experience and learning that Shalltear is under the influence of a World Item unknown to him. Ainz decided to retreat back to Nazarick and begin preparations for his fight against Shalltear.  Ainz has no choice, but to get a World Item from the Treasury. He meets up with Pandora's Actor, his creation and the one who is in-charge of the guild's treasury. After talking to Pandora's Actor, he gives the Ring of Ainz Ooal Gown to him before entering the vault with Albedo. Ainz eventually decides not to use the World Items, since he didn't want to put it to waste and that he will face Shalltear alone without outside interference or help. Moreover, he handed some of those World Items to the Floor Guardians instead to protect them from the effect of their enemy's World Item. He then faces off against Shalltear in an intense battle, using many of his spells against her.  Finally, Ainz finishes her off with the super-tier spell, Fallen Down and thus, he emerges victories against Shalltear.
Returning back to Nazarick, Ainz resurrects Shalltear back to life and hope that her death would cure her mind control which succeeded in doing so. He then started a discussion with the Floor Guardians about strengthening the Great Tomb of Nazarick's defense. While so, Albedo advises Ainz about the lizardmen might have potentially stronger bodies for him to create more, but powerful undead. At E-Rantel, Momon and Nabe are promoted to adamantite class adventurers after reporting on Shalltear's defeat. 
The Show Must Go On! Arc
- Main article: The Show Must Go On! Arc
When Aura began building a duplicate of the Great Tomb of Nazarick, her brother Mare believed she was going to secede from Nazarick. After Ainz arrived he explained its purpose to serve as a fake base to fool outsiders in case of an attack. Upon learning Mare's worry of a possible new rebellion amongst the Floor Guardians, Ainz tried to reward Aura to maintain her loyalty. Despite her reluctance, Aura accepted unless all the other Guardians were similarly rewarded. Later Ainz called a meeting with the Floor Guardians on his plan to implement fringe benefit services. The discussion was productive until feedback from Albedo and Shalltear devolved into a duel of words, forcing Ainz to close the meeting early.
Later, during a walk on the 1st Floor, he was greeted by Demiurge, who congratulated him in his scheme of offering rewards, as the demon believed it to be a method to weed out and traitors amongst the ranks. Rather than deny it to be not the case, Ainz confirmed it to be part of his plan. When he retired to his chambers, he mused to himself of how he could maintain his image as a dignified ruler intact and commented that maybe he should try practicing acting. When he returned to work he was approached by Albedo to include a theatre in the fringe benefit services to provide entertainment for the NPCs. Already receiving the approved signatures from a majority of the Floor Guardians, she proposed that the play Romeo and Juliet be its first production. She insisted that Ainz play a role as Romeo, though he was hesitant to accept her request until she mentioned it would help his acting skills. However, Shalltear barged into his office, revealing to the undead that the play was a scheme concocted by Albedo to steal a kiss from Ainz while she starred as Juliet. Shalltear demanded that a fair voting process is instituted to select the main female lead. So, under Demiurge's judgment, a competition was held for the role of Juliet in all of Nazarick.
Three days before the auditions, Ainz watched Albedo practice her lines. Ainz was amazed at her concentration and when she discovered him watching, Albedo asked if he would help her practice. She manipulated him into playing out a scene of Romeo's death, where Juliet kissed his lips. Just before the Overseer Guardian could perform the act, Shallteat threw an attack at the succubus. The attack resulted in another argument between the Guardians. Ainz so disgusted with their immaturity angrily departed. At the auditions he witnessed their acts, leading the votes to a tie. The two were ultimately disqualified for bribing one of the judges, Aura. Ainz was about to close the competition until he was shocked that Mare had signed to participate in auditions.
The Sealed Evil Tree Arc
- Main article: The Sealed Evil Tree Arc
Ainz Ooal Gown once again using his adventurer alias Momon, to takes on a personal request from the Adventurer Guildmaster of E-Rantel. His mission is to retrieve a rare herb in the northern region of the Great Forest of Tob. Ainz is assisted by Hamsuke and Aura Bella Fiora who guides him to the location of the northern forest. The trio encounters a dryad, Pinison Pol Perlia. Through her, Ainz learns of the awakening evil treant, Zy'tl Q'ae.
Interested, he decides to go and investigate it despite the dryad's warning. Upon the group's entrance into Zy'tl Q'ae's lair, it has fully awakened and upon its head was where the herb they're looking for is located. Seeing an opportunity for an experiment, Ainz summons the Floor Guardians to do battle with the evil treat. Before the battle comes to an end, Ainz delivers the final blow against it and later returns to E-Rantel with the herb in hand.
The Lizard Man Heroes Arc
- Main article: The Lizard Man Heroes Arc
Heeding Albedo's suggestion from before, Ainz decided his next target will be the Great Lake. He orders Cocytus to annihilate the lizardmen and use their corpse to create stronger undead, so they would be able to strengthen Nazarick. While Cocytus has failed to annihilate the lizardmen, Ainz has planned it all along to help him grow individually. It was also just an experiment to use that weak army of theirs for observing how the lizardmen fight.  He then changes his order from annihilation to occupation and for Cocytus's punishment is to be given control and responsibility for the lizardmen once they have submitted to Nazarick. Ainz and his forces confront the lizardmen and start a negotiation. He gives a condition to Shasuryu Shasha and Zaryusu Shasha, that they must face Cocytus in a battle. If they win, he will no longer attempt to bother them. However, if they were to lose or decide not to fight, they must readily submit to him. 
In the end, Cocytus emerges victorious in his battle against the lizardman heroes. Ainz orders Cocytus to summon Crusch Lulu to his presence. He suggests to Crusch Lulu to be his spy within the Lizardman Tribes in exchange for the resurrection of Zaryusu's life.  After Zaryusu was revived by Ainz, the lizardman now view him as their new God who not only has the power of death but life too. 
The Search for Hamsuke Arc
- Main article: The Search for Hamsuke Arc
Ainz who was working in his study back in the Great Tomb of Nazarick is informed by Albedo that Narberal Gamma wishes to see him. Narberal asks if Hamsuke had come into contact with Ainz, but unfortunately, he reports that he had not seen the hamster not since she took her to the surface for some fresh air.
Learning that Hamsuke was in-charge of delivering research materials to 6th Floor although the monsters there have yet to report her arrival, Ainz analytically deduces on the fact that the hamster may have gotten lost along the way. Ainz agreed with Albedo that they should begin conducting a search for Hamsuke and her whereabouts.
Particularly, Shalltear reported back to Ainz in regard to how her minions were able to confront his pet on that floor and where she ran off to. When the female Guardians began to bicker, Ainz decided to have Shalltear and Albedo work together to improve their relationship. Ainz and Narberal then journeyed to the 6th Floor to recruit Mare and Aura in their search.
Eventually, Ainz and Narberal end up getting reunited with Hamsuke who manages to find her master while they were looking for her until now. Ainz orders Narberal to feed Kyouhukou's servant before sending him back to his master. After finding her, Ainz figured that this was also a good way of building a relationship between Hamsuke and NPCs like Kyoukukou who came to her aid as she was a new resident inducted into Nazarick.
The Two Leaders Arc
- Main article: The Two Leaders Arc
Ainz took a bath by using the slime to wash and clean his bones. At the same time, he decides to invite all male Floor Guardians to enjoy the spa in the 9th Floor together. In his bedroom, Ainz is practicing various different poses and speaking phrases. Ainz sees Mare and asked why he is here. Mare responded that he's handing back the invitation that Ainz wrote. The two exchange words and Ainz end up by expressing his love for the NPCs. Hearing what Ainz said, Albedo becomes unable to control her emotions and attempted to rape Ainz. Fortunately, he orders Mare and several Eight-Edge Assassin nearby to get Albedo off while punishing her to three days of solitary confinement.
Later that day, Ainz rides Hamsuke to the Adventurer's Guild headquarters in E-Rantel. He spotted Enri Emmot, who was about to be detained by the authorities. He comes and guarantees for her release from custody. Curious to the reasons, Ainz asked the Guild leader for the content of Enri's request, and finds out that it was relating to the lords of Tob Forest. Back at Nazarick, Ainz scolded Lupusregina Beta for not reporting to him and reminded her to ensure the safety of Enri, Nfirea and Lizzie Bareare.
Ainz along with Aura decided to meet the Giant of the East and Demon Snake of the West. He tries to negotiate with Guu, but it ended up in failure. As a result, he activated his Desperation Aura V and instantly kills Guu and his followers. Meanwhile, Aura captured Ryuraryus who pleads for his life and swear his loyalty to Ainz. He then began turning the corpses of Guu and his followers into an undead and use them to attack Carne Village. Back in Nazarick, Ainz consults Demiurge about the upcoming dinner that he will treat to Nfirea, Enri and Nemu Emmot. After that, Ainz and the male Floor Guardians begin taking a bath together. While Ainz stated that he has a good time in the bath, the Lion Golems attacks the female Floor Guardians to restrain their ignorant behavior. So Ainz and the male Floor Guardians prepare to help them, wishing for a peaceful bath next time if they were to have another one.
Nfirea, Enri, and Nemu are invited to Nazarick to celebrate the success of developing the new potion. Ainz requests Nfirea not to announce the existence of the purple potion after hearing about the attack on Carne Village. Thereafter, they enjoy the luxurious dinner of Nazarick as a reward from Ainz for their hard-work with making the potion. 
The Dark Hero's Story Arc
- Main article: The Dark Hero's Story Arc
Under his alias as Momon, Ainz was counting his savings and allocating the necessary funds to his various projects. He then later sent Narberal Gamma on an errand to collect ore samples for testing the Exchange Box.
Later, he accepted a commission to guide a young noble named Torkel Karan Dale Völkchenheim and his servant, Andre to complete the former's coming of age ceremony. Ainz was initially suspicious of the human's enthusiasm and hostility. He believed that Torkel was an enemy luring them into a trap, but along the way, he realized he was just another of Narberal's persistent suitors. On their way to the goblin village, the party encounters a Gigant Basilisk. Seeing the beast, Ainz ordered the group to run while he disposed of the creature. The battle was witnessed by Torkel who would pass on the tale to his future descendants.
Ainz Raises Money Arc
- Main article: Ainz Raises Money Arc
Ainz gathers the Floor Guardians together in a meeting to announce that he has finally reached a decision concerning the feedback he had received from a survey of all their desires. Since all the requests made by the Guardians were vouchers involving spending time with him, Ainz tries a different tactic and gives each of them three gold coins. He orders the Guardians to use them at their leisure. They are allowed to use the money in any way they one, bar one rule: They must not use it to purchase a living being. He also tells them that should the Guardians need assistance in buying items from the human city E-Rantel, Sebas Tian and Narberal Gamma are available to make the transaction in their stead. After dismissing the Floor Guardians, Ainz worried about what the Guardian may buy, decides to scout out the markets in E-Rantel.
In E-Rantel, Ainz dons his Momon persona, alongside Narberal as Nabe. Listening to the praise from some people on his and Nabe's reputation, he is pleased by status of Darkness, but sighs at the lack of adamantite work. While walking through the streets he notices a vendor hawking a series of Blue Rose merchandise.
Returning back to Nazarick, Ainz is shocked at the idea of the sale of fan goods based on an adventurer team and is impressed that its profitable. Albedo seeing him deep in thought asks him what is wrong, but he tells her its nothing before dismissing the group present. Later Ainz is reviewing some documents that Albedo has given him, and asks on the status of the coins he gave them which Albedo happily reports that the Guardians had used them just as the Supreme Being orders. Please Ainz calls for another meetng eager to hear how they spent the coins.
The Men in the Kingdom Arc
At E-Rantel, Ainz was planning on giving the Floor Guardians a reward for their work and loyalty. Ainz then orders Narberal Gamma to buy and collect iron ore from different locations, so that he can toss it in the Exchange Box.  Meanwhile, he receives a message from Solution Epsilon that Sebas Tian has betrayed them.  When Ainz was informed about Sebas's betrayal, he orders Pandora's Actor to transform as him and test the butler's loyalty whether or not he really betray them.
Once Sebas's loyalty has finally been settled, Ainz teleports to the mansion and he recognizes that Tuare is the older sister of Ninya and decides to accept her into Nazarick as a maid, and under the protection in the name of Ainz Ooal Gown. Returning back to Nazarick, he's informed by Sebas that Tuare has been kidnapped which upset him greatly after swearing his name to protect her. He orders his subordinate to bring Tuare back unharmed and destroy Eight Fingers. 
To cover up the rescue of Tuare and Sebas's identity, he takes on the persona of Momon while Demiurge masquerades a demon invasion on Re-Estize so that it could help him increase his fame if the operation was successful. He also used Marquis Raeven's request as a way to visit the Royal Capital without garnering suspicions from the populace of that area on why he's here. He saw and saves Evileye from Jaldabaoth, a powerful demon lord, who besieges the Royal Capital with an army of demons. Jaldabaoth tells Momon that he came here to find an important item in the Royal Capital. Momon exchanges a few rapid blows with Jaldabaoth while protecting Evileye from one of his attacks, but the demon later made a temporary retreat. 
Outside of the Adventurer's Guild, Blue Roses and Princess Renner gathered all of the adventurers that were present within the city to mobilize. Under their leadership, the adventurers are order to counter-attack and defeated the demon army led by Jaldabaoth. In their battle plan, the adventurer is the bow while Momon is the arrow as nobody except him can fight against Jaldabaoth. When the operation commences, Momon, Nabe, and Evileye found him, who's waiting for them and suspected it was a trap. Momon tells Nabe and Evileye to handle Jaldabaoth's maids while he faces off him. During their fight, Momon and Jaldabaoth crash into a building and walk into a secured room, where Mare was waiting for them. There, Ainz hears Demiurge's explanation about the plan to make Jaldabaoth as the "Demon Lord", due to one of Ainz's previous orders.
Following the plan, Momon confronted Jaldabaoth in a fierce battle and defeated him. Jaldabaoth proposes to Momon that he'll cease the fighting with the condition of allowing himself and his demon army to withdraw.  After the withdrawal of Jaldabaoth and his army of demons, Momon was recognized by the king for his efforts in repelling the powerful demon. Not only was Momon viewed to be the national hero of the Re-Estize Kingdom, but he is even awarded a special sword after he turned down previous offers from the king. 
The Invaders of the Large Tomb Arc
- Main article: The Invaders of the Large Tomb Arc
Ainz returns to Nazarick and gathers all of the custom NPCs in the Throne Hall, so he can grant honors to the NPCs for the successful operation in Re-Estize. After hearing Demiurge's plan, Ainz finally realized that the Floor Guardians are trying to take over the world without his knowledge. He has no choice, but to go along with their plan of world domination. 
Following Demiurge's suggestion, he must find a country to recognize his new nation. Ainz and Narberal Gamma visit Arwintar, the capital of the Baharuth Empire to meet Fluder Paradyne, the strongest wizard of the empire. He meets Fluder and shows his true power to him. Witnessing his power firsthand, Fluder immediately swears allegiance to Ainz. He orders Fluder to send sacrificial pawns to the Tomb. 
As Momon, he escorted the workers to the Tomb and prepares to monitor the massacre. Also, it was his intention to test out the Tomb's defense system if whether it was properly working or not. He chooses Foresight as his sparring partner and sent them to the 6th Floor, where he does battle with them in the Colosseum. Hekkeran Termite tries to deceive Ainz, but he sees through his lie and becomes really upset about it. 
After fighting with Foresight as a warrior, Ainz decides to stop playing around and reveals his true power, and instantly defeated them one by one. Although the members of Foresight manage to let Arche go ahead of them, her attempt to escape was a failure as she was killed by Shalltear shortly thereafter.  After that, he orders Aura and Mare to visits the imperial palace with dragon and threatens the emperor if he does not apologize for the invasion, they will destroy the Empire. 
The Magic Caster of Destroy Arc
- Main article: The Magic Caster of Destroy Arc
In Nazarick, Ainz meets Emperor Jircniv and his delegation to officially apologizes to Ainz Ooal Gown. After Ainz accepted their apology, Ainz then turns Hemel's corpse into a Death Knight right in front of them which causes the imperial delegation to feel terrified as he just created a Legendary Undead being with apparent ease. He agrees with Jircniv's proposal to form an alliance with him and Nazarick, and he also accepts the idea of making his new nation known to the surface world.
After the talks were concluded, Ainz gathered the Floor Guardians in his room. Ainz explains to the Floor Guardians it is only to require a just cause and in order to avoid creating many enemies against them. He also explains to the Guardians that turning countries into graveyards will only damage the name of Ainz Ooal Gown. After hearing Demiurge's explanation to the others, he realized that Jircniv's intention was to form an alliance with the other countries to defeat him. Ainz has then taken Cocytus's suggestion into consideration by crowning himself as the Sorcerer King for the newly-form nation. While so, Ainz tells the Floor Guardians that he will demonstrate the military might of Nazarick in the battle between the Kingdom and the Empire at the Katze Plains. 
Alongside Mare, Ainz went to the Empire's Fortress at Katze Plains. They are welcomed by Nimble Arc Dale Anoch and General Carvain in the fortress to honor the alliance between the Empire and Ainz Ooal Gown. Ainz was requested by the Emperor to cast one of his most powerful spells to destroy the enemy. Ainz tells General Carvain that his army will be arriving anytime. Afterward, Ainz's army of undead are teleported via Gate and he introduces his troops to them which made everyone realize that the small army of five hundred is not to be underestimated. 
In the Katze Plains, the Imperial Army started to separate into two flanks, effectively opening a path for the army of Ainz Ooal Gown. Ainz appears at the front of their army with Mare and Anoch standing at his sides, starts casting a single bright spell. He surveys the area and concluded that there is no player in the Kingdom or no one who is willing to stop him from casting his super-tier spell. With the course clear, Ainz successfully cast the spell known as Iä Shub-Niggurath, consuming the left wing of the Royal Army as a sacrifice to summoned five Dark Youngs. Ainz was overjoyed that he breaks a new record for summoning this much Dark Youngs and ordered them to massacre the Kingdom's Army.
Ainz then takes off his mask and called upon the Imperial Army to cheer for his supreme power. One of the Dark Young was returning to Ainz and headed toward the Imperial Army's direction, which caused every single one of the imperial soldiers to run for their lives, trampling over their own allies. The Dark Young placed Ainz on top of its head and he thought that after casting his most powerful spell, the Imperial Army would charge in. However, seeing the carnage inflicted on the battlefield, it was understandable that the Dark Young did all the work. Still, Ainz decided to continue his assault while Mare was left in charge with his army.
In the battlefield, Ainz sitting on top of the Dark Young came to greet Gazef Stronoff with Climb and Brain Unglaus arriving there too. Ainz then asks Gazef to be his vassal in exchange for stopping this war. However, Gazef politely declines his offer, and instead challenged Ainz to a single duel. Ainz accepted his challenge and asked the two other people to be the witness of their match. Immediately after the battle starts, Ainz stopped time around them except him and began using other spells like Delay Magic and True Death altogether to kill Gazef instantly. With his victory over Gazef, Ainz tells Climb and Brain that he will stop the attack, but demands them to cede E-Rantel and its surrounding area to him. He then returns back to the Empire's fortress with all of his monsters. 
Later in spring, E-Rantel and its surrounding area became a part of the Sorcerer Kingdom. Ainz, Albedo and his army of Death Knights and Death Warriors enter E-Rantel. Albedo then decides to kill a young boy, who is disturbing their arrival march but was stopped by Momon. Ainz stops Albedo and tells her that Momon will serve him as the sword of the Sorcerer King, which he accepts his offer. Afterward, E-Rantel became a peaceful city without bloodshed under the rule of Ainz Ooal Gown. 
The Ruler of Conspiracy Arc
- Main article: The Ruler of Conspiracy Arc
Once the war was over and E-Rantel came under the rule of the Sorcerer Kingdom, Ainz has established the city to become the new capital of his nation. Under his rule, he has to decide on how to proceed from there in ruling his nation by implementing new laws, set up defenses, establishing a new governing body, all of which was a lot more than he could handle. In addition, he moved to the former Mayor's residence and set it up as his base of operations.
Also, it was around this time he took notice of the severe anxiety of the people of coming under the rule of an undead and with all the monstrous beasts that were coming into the city. He noticed the sever absenteeism of adventurers having new quests or anything to do as his minions have mostly taken care of all the problems that the adventurer's used to take. Ainz came up with the idea to change the Adventurer's Guild main goal from being a mainly monster hunting group into real adventurers that would explore the unknown. He met with the city's guild leader to discuss it, intriguing him with this new proposition. Ainz would make suggestions such as providing the support and training through Mare's new underground training labyrinth constructed to train new recruits.
However, he has to make his goals known to all adventurers who would come to his kingdom. In order to attract potential new recruits, he decided to head to the Baharuth Empire to spread the word and to obtain some new supplies for his newly-formed organization. Just before he left, he sent Albedo on a mission to act as an official delegate to the Re-Estize Kingdom to start official ties between the two nations. 
He asked Guild Master Ainzach to accompany him to act as both a guide and adviser, recommending Ainz to see Osk who was known as the best weapons merchant in the empire. Along the way, Ainz became interested about a dwarven sword that Osk has in his collection and was particularly curious about the rune inscriptions on it, which bore a striking similarity to his own world. When he set up the meeting, the two talked a little about each other and start official trade relationship. It was to the point, where Ainz even allows Osk to see his undead face and was one of the few humans who did not bear any ill will towards his undead appearance. They also talked about the Martial Lord of the Empire's Gladiator Arena, where Ainz wanted to participate in a battle against him. Since Osk was the current champion's main sponsor and was a fan of strong warriors, he thought it would be interesting to see the fight happen, so he set up a match between the two.
At the Arena, he met face to face with Go Gin and at that moment, the two complimented each other out of mutual respect. Before the fight begins, Ainz turned off his High tier physical damage nullification effect to fight on more equal grounds against the Martial Lord. They also made a deal that if Ainz were to win, Go Gin would become a part of his nation to help train his new adventurers while if Go Gin were to win, he would eat him, believing he can become more powerful by doing so. After sparring with each other, Ainz finishes the warrior off by striking him with one of the stilettos charged with Fluder's magic and killed him. Afterward, he began to revive the Martial Lord, proclaiming his intentions to the people in the arena for all to hear publicly.
He came back to E-Rantel, satisfied with his accomplishments and at the same time was confused with Emperor Jircniv's sudden declaration of wanting his empire to become his vassal state.  On the other hand, Ainz was more interested in the rune-mark weapon he saw, inviting him to make plans to visit the dwarves and its nation first while leaving the details of the vassalization to Albedo and Demiurge. 
The Pleiades Day Arc
- Main article: The Pleiades Day Arc
Ainz summoned Yuri Alpha to his quarters to resolve a situation between him and Solution Epsilon. The solution had stolen, Ainz's pet which is the sapphire slime, Miyoshi and would not tell him where she had hidden the slime until Yuri compelled her to give him up. After learning that Solution's actions were spurned by jealousy, Ainz tasked Yuri to find if any of the other Pleiades were dissatisfied in any way and see if the maids had any desires that they wished to be fulfilled. While Yuri searched for Shizu and Entoma, Ainz promised to seek out Lupusregina and Narberal. When Yuri reported back to him with her results, he was pleased and decided to put forth a proposal that she proposed, to build an orphanage in E-Rantel.
The Craftsman of Dwarf Arc
- Main article: The Craftsman of Dwarf Arc
Not long after he came back from his business back in the Empire, Ainz has gone and visited the Dwarf Kingdom in order to try to establish official relations with them through trade. More specifically with the objective to understand the runes they crafted into their items and weather if there was a possibility that another player had something to do with them.
Also, it was around this time that Cocytus has sent one of the lizardmen to hand his report in. He took the opportunity to ask the lizardman about information on the Dwarves in which he told Ainz that he does not know much other than there was someone from their tribe who had been to their nation before. The lizardman thinks Zenberu would be the best candidate to ask any information on them for that matter regarding the dwarves. After the talk, he also contacted both Fluder and Ainzach for any more information available. Unfortunately, they happen to know very little about it, so Ainz decided he should head to the lizardman village himself to ask for the information directly.
Thus, he later went to the Lizardman Village to speak with Zenberu Gugu about the Dwarf Kingdom. During his visit there, he happens to offer his blessing for Zaryusu Shasha and Crusch Lulu's newborn child, presenting them a gift to the lizardman chief as a reward for his loyalty. He made arrangement in bringing Zenberu with him to readily act as a guide during his journey to the Kingdom via Azerlisia Mountain range. Also, accompanying him along the way were a few of Ainz's personal picked guards, two of his Floor Guardians being Shalltear, Aura and their respective minions. 
While visiting the Dwarf Kingdom, he held a political meeting with the Regency Council and negotiates several trade deals between their nations successfully. All the while, it was due to Ainz's part for fulfilling his end of the bargain to the Dwarf Kingdom, ending the Quagoa's invasion as well as the Frost Dragons' rule over Feo Berkana. 
The Paladin of the Holy Kingdom Arc
In E-Rantel, a meeting takes place between the Holy Kingdom and the Sorcerer Kingdom, Ainz was requested by Remedios to bring Momon into their nation to fight against Jaldabaoth, but Ainz humbly refuses in doing so because of political reason involving the ongoing situation in E-Rantel. He enlightens them those among his country's citizens who have little contact with these undead activities he has made did not come to fully accept them yet. Ainz also told the envoys that he would need more time for the undead to be completely welcome by its human inhabitants and needs Momon to listen to their concerns. Ainz stated that if he sends Momon out right now, then there is no telling how the discontent of the people of E-Rantel might erupt into uprisings afterward.
Furthermore, Ainz went on and said to the envoys if the Holy Kingdom have anything to offer to him in case he does aid them in their fight against Jaldabaoth. Gustav spoke up, saying they have none right now and it will take time for them to recover and prepare a reward in return. He also made it clear to Ainz that Jaldabaoth is a present threat to their nations as it is leading an army of demi-humans. Ainz still refuses that he needs more time for everything to sort out. Albedo told him that it will take at least five years minimum for the relations between humans and demi-humans in their nation to be solved by then. Due to Ainz's generosity, he responded to the envoys' request by shortening it to three years instead until they're able to come to their aid on time. As a result, Neia thought of having a chance in talking it out with Ainz and voiced her opinion publicly, which he questions later who she was.
Right after Neia introduces herself to Ainz, she urges him to let their nation borrow Momon as soon as possible since they can't afford to wait that long. Before Remedios attempts to reprimand her, Ainz stops her from doing so and he then suggested to Neia when is it the best time to bring him along during the liberation of the Northern Holy Kingdom. Neia replies back to Ainz, saying that he should send out Momon as quickly as a possible or one-day minimum is the very least he can do. When Ainz inquires her even if it ended up hurting his nation in the process, Neia says that as long as it is for the safety of her nation then she is willing to accept it. 
After the meeting, Ainz cast an invisibility spell on himself and waited for Neia outside the inn. He surprisingly spooks her out of nowhere, guiding her to a certain location with no pedestrians passing by. Ainz asked Neia that he wanted to speak with her superior in private, convincing Neia to let him climb through the window. Upon entering through the window open by Neia, Ainz again confronted Remedios and Gustav twice now during their second meeting in regards to their request from last time.
After introducing himself again during a meeting with the Holy Kingdom's envoys, Remedios later obliged to Ainz's request and began moving to a new area for a place to talk privately. He also asks Neia to take part in their political discussion which Gustav too heeds to another one of the Sorcerer King's demands as she accepts it. Arriving at their destination, the meeting began right away when Gustav was the first to start the conversation, inquiring the Sorcerer King for why he came here in the first place.
Thus, Ainz briefs them with his main attention from their last meeting, reiterating the fact that he will employ an entity equal to Momon's caliber. Ainz then replies back in regards to the resistance group which shocked the envoys. In a way, Ainz was already aware of the Holy Kingdom Liberation Army's predicament in the front-lines of war to their utter surprise. Ainz began to explain their circumstance in full detail, he stated that the South's military strength remain untouched, but yet they did not seek to cooperate with the north and conduct joint operations on their own. Ainz believes it to be this way was because there exists a rift between their people and the southern nobles. Ainz even calls the envoys out for their own failure in protecting the Holy Queen as it is going to be the reason for why the South plans to take ownership of who the new Holy King will be after their Queen died in battle. Aware of the southern nobles' nature, Ainz retorted to the envoys that they don't have much of a say in all this when the group cannot hold onto their positions for long without the Holy Queen to support them. Ainz concluded to the envoys that they have nothing left to offer him be it land, titles, trade concessions, and other such privileges. He also warns if the Northern Holy Kingdom actually kept their words on this matter, the possibility of war with his nation exists, depending on what conclusions the next Holy King reaches.
Additionally, Ainz enlightens the envoys of not using their nation’s treasures as a bargaining chip in which cases, spoke of the holy sword belonging to Remedios to be an example. He stated that if they did such a thing by trading something like that of national value, then the most they could do was treat it as having been plundered by Jaldabaoth and later turning the country's treasures over to him after defeating the demon. However, Ainz calls it dangerous as there will be an informant briefing the next Holy King that said wealth was actually obtained from one of them will create a seed of distrust in the group.
Ainz began stating his own conditions and want something else in return for assisting them such as having a control over the Jaldabaoth's demon maids. He believed that Jaldabaoth's underlings could be under the influence of either his skill or magic item used on them. Ainz asks Remedios that he needs strong individuals to be incorporated into his nation anyways to increase their military strength. Remedios told him even if that was the case, she doubts those conditions made by him would be enough for her people to forgive the maids if they're involved in Jaldabaoth's plan. Ainz then told the envoys that it's Holy Kingdom's problem to deal with in swaying the citizens to let go of their hatred or else advised Remedios that he dominated the maids with his magic.
Henceforth, Gustav agreed to all of the conditions listed by Ainz. While so, Gustav brought up the question of who is on the same level as Momon. Ainz answers his question by stating that himself, meaning he will be the one participating in their war efforts. To their bewilderment, Ainz told Gustav and his fellow envoys that he is going to take care of Jaldabaoth, declaring to them that he is just as powerful as Momon and if not stronger than him. Furthermore, Ainz tells them that unlike Momon, he can actually use magic like teleportation. To keep the envoys at ease, Ainz stated that as long as he can find their base, he can safely return to the Sorcerer Kingdom at any time. Although Gustav is reluctant to bring a king from a foreign nation to fight their country's enemy, Ainz told him that he wants to go there and defeat Jaldabaoth while taking control of its servants through his magic. Ainz declared to them that he will not bring an army with him and the fact of nobody other than him alone can defeat Jaldabaoth.
While helping the Roble Holy Kingdom, Ainz has chosen to temporarily give away some of his items like Ultimate Shooting Star Super to Neia as aid. After defeating Buser, the Sorcerer King looted the Bafolk's items for himself and among them, he handed over its magic armor to the girl for additional protection. 
When the battle unfolds between the paladins and the three demi-human generals, Ainz just stood by and watch their match while using the [Perfect Unknowable] spell to hide his presence. At some point, he canceled his spell and decided to assist Remedios, but she left him alone to settle her incomplete match with the demi-humans. Frustrated by Remedios's ingratitude after saving her life, Ainz decided to take his anger out on Nasrene, Vijar, and Halisha who he killed all three of them fairly quick. Afterwards, he went around killing demi-humans that invaded Loyts as well as summoning multiple Soul Eaters to aid him. Along the way, he later revived Neia who died valiantly fighting against the demi-human army.
- In the Web Novel, Ainz was thought to be one of the Thirteen Heroes.
- Momonga renames himself as Ainz Ooal Gown so that guild members or players may know its existence.
- Nigun of the Sunlight Scripture assumes Ainz's true identity happens to be one of the Evil Deities.
- Under his adventurer persona as Momon, he holds the moniker 'Dark Hero' that refers to his black plate armor and heroic combat prowess. Evileye speculated that Momon is a Godkin, beings with the blood of Players in their veins, due to his display of power that surpasses humans.
- The Slane Theocracy's cardinal have almost mistaken him for one of the Six Great Gods, Surshana known as the God of Death, but quickly dismiss that idea.
- Both the villagers of Carne Village and the lizardman tribes of the Great Lake have built their own respective statue of Ainz Ooal Gown as a sign of loyalty to him.
- Due to Ainz's illusion spell, the Swords of Darkness believed that judging from his facial appearance which is black hair and eyes visually, they see people like him are commonplace in the South.
- (To the Staff of Ainz Ooal Gown): "Should we get going, symbol of our guild? No, that’s not it. let us go, symbol of our guild."
- (To Demiurge): "It is truly beautiful. These stars were meant to decorate me. I will leave my body here, in order to obtain this jewel box that belongs to no one."
- (To the Knights): "You dare to chase little girls, but don’t have the courage to stand against enemies?"
- (To the Knights):"Do not cause any trouble here. If you choose to not listen to my advice, next time you and your country will burn together."
- (To Albedo about Humans): "Well, upon meeting the humans here, I could only muster enough empathy to treat them as insects, but after conversing with them, I’m starting to see them as small animals."
- (To Nigun): "The deal that I mentioned before is that I hope that you would quietly surrender your lives, this way you can be spared from physical pain. Otherwise, if you resist, which would be very stupid of you would have to pay the cost of dying in despair and misery."
- (To his Guild Members): "My friends, what do you think about me hogging this glorious name? Will you be happy? Or displeased? Tell me if you have any feedback, tell me this name isn’t mine alone. I will change back and use Momonga without hesitation."
- (To Albedo about Shalltear): "I am the one known as the Guildmaster of Ainz Ooal Gown. When engaging in PvP, the actual chance of victory is high, invincible against even those with flawless builds. How can I lose to the type of person who solely relies on their attribute? Furthermore, the most important fact is the strong bond I have with Peroroncino. Know that this battle was over even before it had begun Shalltear."
- (To the Unknown Enemies) “I will definitely make you deeply regret your own foolishness. Do not think you can get away so easily when you anger us, Ainz Ooal Gown.”
- (To Himself): "I am Ainz Ooal Gown. With that name at stake, there can be no defeat."
- (To Himself): "Hooh...Ainz-sama's plan, huh. I see. A special plan concocted by someone with the same name as me. Making the Baharuth Empire ally with and struggle against Nazarick was part of that plan too, huh...I have no idea what that's all about. If only I could ask this Ainz fellow about it!"
- (To Shalltear): "Realize now, Shalltear. You face Ainz Ooal Gown, with the combined might of all Forty-One Supreme Beings from the beginning, you had no chance of victory."
- (To Himself): "Repaying good with good and evil with evil. This is the norm of the world."
- (To Gustav about Neia): "I gave her those orders because I felt she could carry them out. However, interfering in the matter by weight of your position as a superior is comparable to slighting my judgment. That displeases me to an extent."
- (To Neia): "Umu...Neia Baraja. Don't make me repeat myself so many times. Failure is the mother of success. The consequences of not relying on me and instead thinking for yourself, even if they should end up being failure, should not be feared, but embraced. This is because they are the failures necessary for success."
- (To a foreign citizen formerly captured by Bafolks): "Originally, the weak like yourselves should have been defended by the Holy Kingdom, those who should have been strong...I really do pity you. If you were under my protection -- under the protection of my country, the Sorcerer Kingdom, something like this could not possibly happen. That is because I would have used all my strength to protect the people and strike down the Bafolk."
- (To Himself in front of the foreign citizen): "Even I would be oppressed if I were weak. Therefore one cannot forget to seek strength. I need to engrave into my heart the fact that beings of comparable power to myself most definitely do exist."