Pleiades

Pleiades (プレアデス) is the combat maid squad of the Great Tomb of Nazarick. Its members originally only served as Nazarick's last line of defense, but Ainz has assigned them more tasks after the tomb was transported.

Background
The Pleiades is the combat maid squad of Nazarick, programmed as sisters. Unlike the other homunculus maids under the orders of Pestonya Shortcake Wanko, the Pleiades members do not have any skills for housework and instead fight under Sebas's command as a final raid boss team right before the throne hall. All of them are women of unsurpassed beauty, each with a different type of appeal. After the teleportation to the New World, three of them are working outside of the tomb. This seems to be because they are amongst the rare NPCs from Nazarick who can easily disguise themselves as humans.

The Pleiades can be organized in two different formations. One is the "Pleiades Six Stars" and the other is the "Pleiades Seven Sisters". These formations can be switched by changing the leader to Sebas or the Lastborn of the Pleiades. The "Pleiades Seven Sisters" activates in volume 6, yet Ainz does not allow the Lastborn to move and thus Yuri Alpha becomes deputy leader.

The Undead King Arc
Momonga orders the Pleiades to guard the 9th floor for possible intruders in the Great Tomb of Nazarick.

The Dark Warrior Arc
Ainz Ooal Gown choose Narberal Gamma to be his adventurer partner and infiltrate the fortress city of E-Rantel. Their plan is to become famous adventurer so that they can gain more information about this world.

The Bloody Valkyrie Arc
In E-Rantel, Shalltear Bloodfallen's task was to enslave any criminals who knew martial arts or magic talent. While Sebas Tian and Solution Epsilon have been ordered by Ainz to disguise themselves as humans, and gather information. In particular, the roles they played were an elderly butler and a spoiled rich princess. As well in E-Rantel, Narberal stay at the inn and wait for Ainz's instruction when he returned.

The Men in the Kingdom Arc
After being questioned by authorities, Sebas leaves while Solution finally decides to contacts Ainz and informing him that Sebas might have gone rogue. After confirming Sebas' loyalty, Ainz then switch Pleiades Six Star System to Pleiades Seven Sister System since Lastborn of Pleiades won’t be move, Yuri Alpha will be the temporary leader instead.

Pleiades participated in Demiurge's plan to make Momon and Nabe a heroes in the Re-Estize Kingdom. Pleiades will act as Jaldabaoth's underlings with their face disguised with a mask with the exception Narberal, who will be as Nabe to assist Momon During the disturbance. Operation Gehenna commences, Nabe will fight against Lupusregina, Solution and Entoma, while Evileye will fight against Yuri and CZ until Jaldabaoth ordered a retreat.

The Invaders of the Large Tomb Arc
Before the slaughter of the workers, Ainz returns to the tomb, leaving Narberal and Pandora's Actor at the adventurer's encampment. Pleiades meet Green Leaf on the surface of the Tomb. Yuri Alpha orders the Nazarick Old Guarders to fight against Green Leaf. Nazarick Old Guarders easily defeat Green Leaf without having to deploy any of the other servants.

The Magic Caster of Destroy Arc
When the delegation from the Baharuth Empire, arrived at the doorstep of Nazarick, the battle maids entertained them, serving them delicious drinks. The members of the delegation were impressed by their discipline and attractive looks.

Strength
With all of them except Sebas being under level 65, the Pleiades's combat capability is quite low considering the role they have been given. This is because the final defense line of Nazarick is actually concentrated on the 8th floor. The actual purpose of the Pleiades is just to delay the invaders and allows all the guild members to gather in the throne hall and greet the invaders like villains in fiction. Despite this, the low power levels in the new world make them equivalent to legendary monsters.

Known Members

 * Sebas Tian - Leader of Pleiades Six Stars System
 * Yuri Alpha - Deputy Leader
 * Lupusregina Beta
 * Narberal Gamma
 * CZ2128 Delta
 * Solution Epsilon
 * Entoma Vasilissa Zeta
 * Lastborn of Pleiades - Leader of Pleiades Seven Sisters System

Trivia

 * The dual organization of the Pleiades refers to two different meanings of the word "Pleiades". In Greek mythology, the Pleiades refer to the seven sisters, daughters of the titan Atlas, while in astronomy the Pleiades is a star cluster called the "Six Combined Star" (六連星) in Asia.
 * The homunculus maids of Nazarick think of the Pleiades as a kind of idol group, with CZ the most popular among them.