Aureole Omega

Aureole Omega (オーレオール・オメガ) is an Area Guardian of the Cherry Blossom Sanctuary and the leader of the "Pleiades Seven Sisters," the battle maid squad of the Great Tomb of Nazarick.

She is in charge of the Teleportation Gates in Nazarick and protecting the Staff of Ainz Ooal Gown in the Cherry Blossom Sanctuary.

Appearance
Aureole Omega wears the traditional attire of a miko which includes a pair of red hakama (long, divided trousers) and a white haori (kimono jacket).

Personality
Solution knowingly sees her sister, Aureole Omega to be a rational person, since she wouldn't have came to the same decisions as Sebas did. Her sister, Yuri Alpha describe Aureole as someone who is high-spirited. Yuri has also imagined the thought of Aureole crossing her arms with an adorable smile on her face. Her manner of speaking is done in a calm, gentle voice.

Background
Aureole Omega is the leader of the "Pleiades Seven Sisters" and the Area Guardian of the Cherry Blossom Sanctuary that controls all the teleportation gates in Nazarick. She is the only human NPC of Nazarick that possesses eternal life.

According to her older sister Yuri Alpha, Aureole Omega is usually the person who would know the movements and whereabouts of all of the Seven Sisters.

The Emissary of the King Arc
When Ainz sent out his Death Knight to interview each of the Floor Guardians, Aureole Omega noticed its presence in using the Gates. Seeing that the undead wasn't an enemy, she allowed it passage.

The Men in the Kingdom Arc
Ainz switches the Pleiades from the Six Stars to the Seven Sisters. While so, Ainz does not allow Aureole Omega to move from her current position and thus, Yuri Alpha becomes temporary leader of the Seven Sisters.

The Two Leaders Arc
When Nfirea, Enri and Nemu were teleported to the 9th Floor during their visit in Nazarick. During the transition, Enri briefly caught a glimpse of Aureole Omega.

The Pleiades Day Arc
Yuri Alpha contacted her youngest sister to confirm the location of Shizu Delta who was on the 6th Floor of Nazarick. With permission from Ainz, Aureole Omega informs Yuri that she is allow to take two of her own servants outside the Cherry Blossom Sanctuary.

The Paladin of the Holy Kingdom Arc
To support the summoned Evil Lord Wrath and Erich String Orchestra in their upcoming battle with Ainz, Aureole Omega was ordered by Albedo to buff the five Greater Doppelgängers who took on the form of all her Pleiades sisters except Narberal Gamma beforehand. Ainz did not expect Aureole Omega to play a major role in this battle until acknowledging that the Doppel-Pleiades were much stronger than they are normally supposed to be capable of doing. He realized that Aureole Omega is involved with the match, considering on the fact that she must have been the one who is responsible for enhancing their group's strength and abilities.

Abilities and Powers
Aureole Omega is in charge of overseeing all the teleportation gates in the Great Tomb of Nazarick. If an intruder attempts to enter through it, she will use some sort of unknown portal to teleport or divert the intruders into the isolation area of her choice. When Ainz switches the Pleiades from the Six Stars to the Seven Sisters System, she is now the leader of the Pleiades.

Additionally, she has servants like Uka-no-Mitamas and Ootoshis under her command. According to Yuri Alpha, her sister's servants have the sacred duty of defending Aureole Omega's domain, the Cherry Blossom Sanctuary on the 8th Floor of Nazarick.

Like Pandora's Actor, Aureole Omega is also a level 100 Area Guardian. She specialized in commander-type classes. As a commander, she could issue orders which buffed her allies like CZ Delta. Thanks to Aureole Omega, CZ Delta is able to overcome the level difference between herself and Ainz to the point that she can successfully interrupt his spell casting twice. Ainz viewed Aureole Omega as a wild card and an all-rounder.

Active

 * Gate: Summons a portal, allowing travel of a large number of people over great distances. It is considered to be the highest tier of teleportation magic.

Ainz Ooal Gown
Aureole is entrusted with the protection of the Staff of Ainz Ooal Gown in the Cherry Blossom Sanctuary when it is not in the possession of her master, Ainz.

Yuri Alpha
While the two are sisters, they still maintain a cordial relationship when carrying out their master's order. Reasonably, she is willing to help out Yuri on the job, lending the maid her own minions for assistance if need be. Yuri sees Aureole Omega as an adorable little sister to the point that Yuri had even refer to the maid by her given nickname as "Au-chan."

Narberal Gamma
Narberal apparently dislike almost all the humans she is around with. However, her younger sister Aureole Omega is an exception to those she hate. For that reason, Aureole is probably the only human being Narberal does not in anyways hold any hostility towards.

Solution Epsilon
Her older sister Solution viewed Aureole Omega as someone who is not consider a normal human being, since she is practically immortal.

Albedo
Albedo is likely her superior as the Overseer could recruit Aureole Omega to help her on buffing the Doppel-Pleiades before they begin battle against Ainz.

Trivia

 * There is an unknown female NPC in the picture of all 100 level NPCs in Nazarick. As the NPC's clothes is similar to that of miko, it was implied to be Aureole Omega in such attire.
 * She is the original owner of the World Item in the 8th Floor that was given to Shalltear Bloodfallen.
 * Her name is finally revealed in the bonus booklet of the Overlord Movie, The Undead King.
 * She is the only member among the Pleiades to not take part in neither Ainz's or Demiurge's operation outside Nazarick until Albedo used her to buff the Doppel-Pleiades.

Quotes

 * (To Yuri Alpha): Yes. When Ainz-sama graced me with his presence, I received permission to send up to two of them outside the Cherry Blossom Sanctuary at any one time.