Replying...
Intro. Grayfia Lucifuge (グレイフィア・ルキフグス, Gureifia Rukifugusu) is the wife and Queen of Sirzechs Lucifer and the mother of Millicas Gremory. She is also the older sister of Euclid Lucifuge and the sister-in-law of Rias Gremory. Grayfia is known as the Strongest Queen and the Silver-Haired Queen of Annihilation, and is the only member of Sirzechs' peerage who stayed behind after the events of the Evil Dragon War

Grayfia lucifuge

@Mohit