Luminous Valentine (ルミナス・バレンタイン ruminasu barentain) is a Demon Lord member of Octagram and the True Ruler of Holy Empire Ruberios. She is the ruler of all the vampires and one of the oldest demon lords.
She is a cute silver-haired girl. Her heterochromatic eyes glisten in deep crimson and light sky blue. This, among her many strikingly beautiful features, is the most prominent one. What garners the most attention, are two pure white teeth that peak from within her small lips. When her small lips part, they reveal a set of pure white fangs. She is commonly seen wearing gothic dresses but seems to have a penchant for maid uniforms too.
Luminous is a usually haughty individual who basks in her superiority when sitting on her throne or when acting out her official position as a ruler, however, she has no problems with pretending to be a maid when it comes to hiding her true identity.
She thinks of Chloe as her savior and possibly has feelings for Chloe
She is somewhat envious of how close Rimuru is to Chloe but other than that they seem to have a mostly positive relationship
Veldora destroyed her original kingdom and she has never forgiven him, and all attempts to get on her good graces have ended in failure for the dragon. This doesn't help that Veldora accidentally reveals her name and her role as a Demon Lord.
A genuine Rank S Disaster-class Demon Lord, specifically a True Demon Lord. Luminous was strong enough to defeat Hinata Sakaguchi in the past and was able to completely nullify her Usurper. She has the ability to resurrect herself or other from the dead due to her Ultimate Skill, she is also able to heal herself at an incredibly fast rate.