Grayfia Lucifuge

Grayfia Lucifuge is the Maid of the Gremory Clan, the wife and Queen of Sirzechs Lucifer, Rias' older sister-in-law, and the mother of Millicas Gremory. She is a Queen known as the Strongest Queen and the Silver-Haired Queen of Devourer.

Appearance
Grayfia is an attractive woman appearing to be in her twenties, with silver hair and matching eyes. Her hair, which flows all the way down to her back, features a long braid on each side with small blue bows at the ends, while the rest is let down, ending in twin braids. In most of her appearances, she is seen wearing a blue and white French maid outfit with long sleeves and a white maid headband over her head, with red lipstick as a cosmetic accessory.

Personality
Grayfia has a very strict personality, and is often exastrabated by her husband. She also does not like admitting her relationship to Sirzechs while she's "on the job", to the point of pinching Sirzechs' face if he mentions it, and denying it.

History
Grayfia comes from the House of Lucifuge, a family of Pure-Blooded Devils from the Extra Demons whose family served under the original Lucifer. Grayfia was originally from the Old Satan Faction that opposed the Anti-Satan Faction, where she stood in the front lines as one of the most powerful Devils. It was during that time that she met Sirzechs and fell in love with him. The two of them married each other after the end of the conflict between the Old Satan Faction and the Anti Satan Faction, eventually giving birth to a son. Their romance became a well-known romantic story among the young Devils and was even made into a movie.

The Red Dragon Emperor's Awakening
Grayfia made her first appearance in Volume 2, stopping Rias from having sex with Issei to break off her engagement. She later arranges a Rating Game between Rias and Riser Phenex, the third son of the Phenex Family and Rias' fiance at that time, with the consent of Rias' family.

Birth of the Breast Dragon Emperor
In Volume 4, Grayfia accompanies Sirzechs to the human world, when Sirzechs goes to the Hyoudou Residence to visit Issei's parents as well as for Rias' class observation day.

In Volume 5, she and the other maids and butlers of the Gremory Clan welcomed Rias and her peerage who returned to the Gremory Region, preparing a carriage for them.

In Volume 6, she is seen to be taking care of Issei along with her son, telling her son not to call her mother when she is doing her job.

The Heroic Oppai Dragon
In Volume 8, she took a day off as the Maid of the Gremory Clan and visited the Hyoudou Residence as Sirzechs' wife and Rias' sister-in-law. She went to inspect the house and to see how Rias is doing, as she is going to be the future heir of the Gremory Clan. She later acted as "Satan Yellow" during the trial for Issei and Rias at the Ruins of Connection before properly acknowledging them as the Master and Mistress of the Gremory Clan.

In Volume 11, she accompanied Sirzechs to the Hyoudou Residence when Sirzechs is getting the confirmattion from Issei, Yuuto and Akeno for their middle-class promotion test.

In Volume 12, she and the members of Sirzechs' peerage goes to the front line to fight the Jabberwocky but could not make much progress due to its high regeneration ability. They were later successful in defeating the Jabberwocky after Issei (in Super Gigantic Balance Breaker form) assisted in the battle and uses the Longinus Smasher to destroy the Jabberwocky without a trace.

Powers & Abilities
Grayfia is Sirzech's Queen and a very powerful Devil on par with the Four Great Satans, having an extreme amount of demonic powers. She uses Ice-based magic.

Trivia

 * Sirzechs Lucifer was once nearly killed by Grayfia for taking photos of her sleeping.
 * Grayfia once challenged Serafall Sitri for the title of Leviathan.
 * Grayfia's last name, Lucifuge, is a reference to Lucifuge Rofocale, a demon in charge of Hell's government and Lucifer's subordinate. Her role as Sirzechs' wife and Queen, as well as her family's lineage of serving the original Lucifer, justify this reference.
 * Grayfia's height is 174 cm. (5 feet 10 inches) according to the visual book with her data, making her the second-tallest female character in the series after Kalawarner.
 * Grayfia bears a near-exact resembleance to Sakuya Izayoi of the Touhou Project Series.
 * The fact that Grayfia uses a harisen on her husband is reminiscent of a manzai act, a Japanese equivalent of a comedy duo where the tsukkomi (straight man) hits the boke (funny man) with it in response to their jokes or idiocy. In Grayfia's case, she is the tsukkomi while her husband is the boke.