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 Ooal Gown has assigned them more tasks after the tomb was transported.

Background
The Pleiades is the battle maid squad that hailed from the Great Tomb of Nazarick. This unit was programmed to have their members as sisters with the exception of Sebas Tian. While the members of the Pleiades referred to each other as sisters, they were not actually true sisters. This was due to the fact that each one of them was made by separate creators. They were simply designed to act that way around one another.

During the old days of YGGDRASIL, the Pleiades are programmed to be under the command of Sebas. Working together alongside Sebas, the Pleiades are a final raid boss team right that the remaining invaders would battle before challenging the 41 guild members of Ainz Ooal Gown in the Throne Room.

Nonetheless, all of its core members are women of unsurpassed beauty, each with a different type of sex appeal to them. After Nazarick was transported into the New World, three of them (Narberal, Lupusregina, and Solution) are apparently working outside of the tomb as of now. Ainz seems to have picked them because they are one of the rare NPCs from Nazarick who can easily disguise themselves as humans without drawing suspicions.

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 Tian or Aureole Omega. Although the "Pleiades Seven Sisters" have been activated after Ainz tested Sebas Tian's loyalty, he still does not allow Aureole to move freely at the moment. Hence, he decided to make Yuri Alpha become the Pleiades's deputy leader to maintain command over the sisters.

The age range from oldest to youngest siblings are ranked accordingly about the Pleiades: Yuri Alpha > Lupusregina Beta > Narberal Gamma & Solution Epsilon > CZ2I28 Delta & Entoma Vasilissa Zeta > Aureole Omega.

The Undead King Arc
During the day of YGGDRASIL's shutdown, Momonga heads for the Throne Room in the Great Tomb of Nazarick and came across the Pleiades midway during his walk there. Although Momonga admits to having accidentally forgotten their character names, he does recall his guild members bickering with each other over the naming of these NPCs. He later instructed the battle maids to follow him on his way to the Throne Room and then have them on standby after seating himself to the Throne of Kings.

After being transported into the unknown New World, Momonga orders the Pleiades to guard the 9th Floor for possible intruders in Nazarick. They also guard and escort Momonga around Nazarick before the latter came up with an excuse to not have anyone be allowed in following him wherever he goes.

The Dark Warrior Arc
Ainz Ooal Gown has chosen to have Narberal Gamma be the person as his adventurer partner and infiltrate the fortress city of E-Rantel. Their plan is to become a famous adventurer so that they can gain more information about this world. Later, he figures that the better choice for who should have been his partner given the present circumstances was supposedly Lupusregina Beta rather than Narberal.

The Bloody Valkyrie Arc
In E-Rantel, Shalltear Bloodfallen's task was to enslave any criminals like Brain Unglaus who knew about martial arts or magic talent. While as for Sebas Tian and Solution Epsilon, they 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 heiress who hailed from a city in some part of the Baharuth Empire. As well in E-Rantel, Narberal was given the order to stay at the inn and wait for further instructions from Ainz when he returned.

The Show Must Go On! Arc
Aura informed Albedo that the Pleiades opted to refrain from entering the Romeo and Juliet auditions, for the role of Juliet.

The Two Leaders Arc
Under the order of her master Ainz, one of the Pleiades, Lupusregina Beta, was dutifully stationed at Carne Village and protect Nazarick's assets: Lizzie Bareare and Nfirea Bareare. At first, she was met with harsh criticism by Ainz at first for not taking her job seriously as she failed to report the news to him about there being Giant of the East and Demon Snake of the West. However, Lupusregina amends for her mistake by managing to vanquish the zombified Giant before it tries to kill Nfirea. Later on, Ainz would also appoint her the task of protecting Enri Emmot and Nemu Emmot too.

The Dark Hero's Story Arc
During the Floor Guardians' meeting on what to ask Ainz as a compensation, members of the Pleiades like Lupusregina Beta and Solution Epsilon were mentioned as potential candidates in helping with their search for women's clothing. At the same time, Yuri Alpha was given the duty of hosting the auction held between bidders as Albedo, Shalltear Bloodfallen, and Mare Bello Fiore.

The Maid Tea Party Arc
The Pleiades, with the exception of Lupusregina and one other, assembled at the Great Tomb of Nazarick to hold their monthly report and tea party.

The Men in the Kingdom Arc
and The Men in the Kingdom II 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 switches the Pleiades Six Star to the Pleiades Seven Sister. Since Aureole Omega won't be moved from her post, Yuri Alpha will be the temporary leader instead.

The Pleiades participated in Demiurge's plan to make Momon, a hero in the Re-Estize Kingdom in the public eye as well as secretly looting valuable resources from the nation's capital, Re-Estize. The maids have been given the role of acting as Jaldabaoth's underlings with their faces disguised with masks with the exception of Narberal Gamma, who as Nabe, assisted Momon during the disturbance. After Operation Gehenna commences, Nabe was tasked with the duty of fighting against Lupusregina, Solution, and Entoma, while Evileye will deal with both 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. When waiting to bide their time to strike at Nazarick, Dragon Hunt encounters the Pleiades on the surface of the Tomb while trapped in a pincer movement. Yuri Alpha orders the Nazarick Old Guarders to fight against Dragon Hunt. Over the course of time, the Nazarick Old Guarders managed to slowly outmaneuver the worker group and defeat them without needing to deploy any of the other servants for assistance.

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. At the same time, they felt the Pleiades were stronger than the Death Knights as none of the maids seems to be frightened by the legendary undead.

The Pleiades Day Arc
Upon completing all her assignments for the day, Yuri Alpha returned to her quarters where she found Narberal Gamma and Lupusregina Beta relaxing. Yuri tensed with frustration scolded them for their uncouth behaviors was called by Ainz Ooal Gown to assist him in a dispute with her sister Solution Epsilon, who had stolen his bathing attendant Miyoshi. Yuri manages to compel the slime to give up her captive and return him to Ainz. Rather than punish her, Ainz sees it as a sign of his neglect and decides to have Yuri investigate the desires of the other Pleiades.

Ainz’s Ambition Arc
The Pleiades were summoned by Albedo to attend Ainz's quarters during his three-day vacation along with the entire Nazarick work staff.

The Paladin of the Holy Kingdom Arc
and The Paladin of the Holy Kingdom II Arc The Pleiades, specifically Yuri, Lupusregina, Solution, Shizu, and Entoma, under the alias as Jaldabaoth's Demon Maids were used as a bargaining chip in the negotiations with the Holy Kingdom Liberation Army and the Sorcerer Kingdom. Though the resistance had yet to confirm these maids in the Northern Holy Kingdom, they agreed to allow Ainz to take control of them once he had dealt with Jaldabaoth.

During the Sorcerer King's fight with Jaldabaoth and his associates, Erich String Orchestra, a group of Greater Doppelgängers transforms into every member of Pleiades with the exception of Aureole Omega and Narberal Gamma. These doppelgängers borrowed the Pleiades equipment and received a buff from Aureole Omega ahead of time prior to encountering and fighting Ainz in a match.

In the end, Jaldabaoth defeated the Sorcerer King while heavily covered in wounds, later making a retreat after the match to recuperate. Despite losing to him, Ainz was able to successfully freed one of their demon maids, CZ2I28 Delta from Jaldabaoth's control and left it in the hands of the Holy Kingdom Liberation Army.

Strength
With all of them except Sebas and Aureole Omega 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, allowing all the guild members enough time to gather together in the throne hall and greet the invaders like villains in fiction.

Despite being looked upon as weak by the YGGDRASIL standard, the levels of each member in this group from the New World's perspective make them equivalent to legendary monsters.

While the Pleiades each had completely different job abilities, their maid skills were all equally the same. For instance, they can still perform housework like the Homunculus Maids under the command of Pestonya. In a sense, they could substitute for each other in a professional capacity.

In the Web Novel, it was noted every member of Pleiades is equipped with a battle maid uniform that they wear in direct combat. Considering its defensive properties, rather than treating each respective attire as battle maid clothes, they were functioned exactly more like full plate armor. Additionally, the armor was imbued with top-grade magic through rare data crystals that only players who are over level 90 could get were used for it.

Trivia

 * The dual organization of the Pleiades refers to two different meanings of the word "Pleiades." In Greek mythology, the Pleiades refers 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.
 * The members of the Pleiades called each other sisters, but unfortunately, they were not true sisters, since they were made by separate creators. They were simply designed to be that way.
 * The name of the Pleiades maid group had its own name etched into the title of the Pure Pure Pleiades series.

Gallery
Plejady