Queen of Nightmares

About

Luminous Valentine (ルミナス・バレンタイン) is a Demon Lord, the fifth seat of the Octagram, and the True Ruler of Holy Empire Ruberios. She is the ruler of all the vampires and one of the oldest demon lords.

(Source: Tensei Shitara Slime Datta Ken Wiki)

Anime

Supporting That Time I Got Reincarnated as a Slime Season 3

Supporting That Time I Got Reincarnated as a Slime: Visions of Coleus

Supporting That Time I Got Reincarnated as a Slime Season 2 Part 2

Supporting Tensei shitara Slime Datta Ken 3rd Season: Kanwa - Diablo Nikki

Main That Time I Got Reincarnated as a Slime Season 3: Digression - Luminous Memories

Manga

Supporting That Time I Got Reincarnated as a Slime