As the Supreme Being's elite chosen NPCs, the denizens of Nazarick show proper respect to the Floor Guardians for their immense authority and terrifying power.
Floor Guardians roles were similar to stage bosses of a dungeon. Each of them manages the defensive system of their own floor respectively. For that reason, all of them have the highest authority among the NPCs, and most of them (except Victim) are very powerful level 100 NPC. After the teleportation, they closely serve the guildmaster Ainz Ooal Gown. Now given more freedom and additional duties, they have been slowly gathering resources and monsters to strengthen Nazarick.
The Undead King Arc
- Main article: The Undead King Arc
Momonga, the last of Forty-One Supreme Beings, sensing a disturbing change in the state of the world summoned the Floor Guardians to the 6th Floor. At the Amphitheater, with exception of Gargantua and Victim, the Floor Guardians had gathered. Here they submit their absolute loyalty to Momonga.
The Bloody Valkyrie Arc
- Main article: The Bloody Valkyrie Arc
During the rebellion of Shalltear Bloodfallen, the Floor Guardians gathered in the 10th Floor of Nazarick to discuss how to deal with the situation. After learning that Shalltear was possibly brainwashed by a World Item, Ainz opted to handle her himself. Aura and Mare, armed with World Items escorted Ainz to Shalltear's location and were ordered to contain the surrounding area. The other Guardians were ordered to remain in Nazarick, with Cocytus ensuring they did not come to their master's aid and disturb the battle.
The Lizard Man Heroes Arc
- Main article: The Lizard Man Heroes Arc
The Floor Guardians convened in the throne chamber of Nazarick. Cocytus appeared before his master and his fellow Guardians to answer for his failure in annihilating the Lizardmen Alliance. The Floor Guardians witnessed Cocytus' plea to spare the lizardmen, and proposed conquering them instead. With the persuasive argument from Demiurge the petition was accepted with the full support of the Guardians.
The Two Leaders Arc
- Main article: The Two Leaders Arc
To strengthen his bond with the Floor Guardians, Ainz invited Demiurge, Cocytus and Mare to visit the Spa Resort In Nazarick. While the session was supposed to be a private one with the male Floor Guardians, Albedo had also planned a similar bonding session with Aura and Shalltear. The female Guardians' lewdness earned them the ire of the Lion Golem which attacked them in the women's section, prompting the men to aid them.
The Dark Hero's Story Arc
- Main article: The Dark Hero's Story Arc
The Magic Caster of Destroy Arc
- Main article: The Magic Caster of Destroy Arc
The Floor Guardians were in attendance in Ainz's throne room when the Imperial delegation from the Baharuth Empire arrived. After Ainz agreed to an alliance with Emperor Jircniv Rune Farlord El Nix, the Guardians and their master convened for a private meeting. Demiurge proposed they form their own nation and name Ainz Ooal Gown their king. Cocytus then bequeath Ainz the title of Sorcerer King to mark the occasion.
It is obvious that the Floor Guardians (except Victim) have their own high combat ability, yet there are still other NPCs outside the group who're considered to be stronger than them in Nazarick. For example, the most powerful NPC of Nazarick is Rubedo, and it is confirmed that some Area Guardians like Guren, when optimized in battle, are stronger than relatively weak Floor Guardians.
Among the Floor Guardians, Shalltear and Gargantua are considered as potential contenders of being likely called the strongest Floor Guardian. However, since Gargantua doesn't have a will of its own, Shalltear may hold that title in terms of intelligence. Mare is also another possible candidate who can compete for first and second place with her, following Sebas.
- Floor Guardians have personal bodyguards, estimated to be level 75, to guard them when they travel outside of Nazarick.
- Most servants over level 80 in the Great Tomb of Nazarick were direct subordinates of a Floor Guardian and those who were not, were few and far in between.
- Similar to how nobles pride themselves with their bloodlines, Floor Guardians take pride and dignity to being personal creations of the Forty-One Supreme Beings.
- According to Maruyama's conversation with an interviewer, there are going to be multiple countries in the middle of the continent and they will eventually make an alliance and fight against the Floor Guardians in a huge war.
- Aura and Mare are the only known Floor Guardians to share guarding a floor, where as every other floor usually only has a single Floor Guardian assigned to it.