Luminous Twilight Valentine

Luminous Twilight Valentine (often referred to simply as Luminous Valentine) is a powerful Demon Lord in the anime That Time I Got Reincarnated as a Slime. She holds the fifth seat in the Octagram (the council of Demon Lords) and is the true ruler of the Holy Empire of Lubelius, secretly governing it while posing in other roles at times (such as a maid). She is also the queen and ruler of all vampires, recognized as one of the oldest and most ancient Demon Lords.

In the anime adaptation, she appears as a youthful, late-teen girl (looking around 15–16 years old) with an elegant yet captivating beauty. She has striking silver hair and heterochromatic eyes—one deep crimson and the other light sky blue—along with prominent pure white vampire fangs that hint at her true nature. Her typical outfits include gothic dresses or maid attire, giving her a refined, aristocratic vibe.

Personality-wise, she often comes across as haughty and superior, especially in formal or throne settings, but she develops a respectful (and sometimes teasing) relationship with Rimuru Tempest, eventually forming alliances like a non-aggression pact. She is also known by titles such as the "Queen of Nightmares" and plays a key role in the Demon Lord dynamics.

Her full name "Luminous Twilight Valentine" and deeper backstory elements (like her origins tied to Twilight Valentine) receive more focus in later anime content, including side stories and specials like Visions of Coleus.