The Demon King: He is the progenitor of all other demons. Sharing his blood creates new demons, making him directly responsible for turning Nezuko and killing Tanjiro's family.Leader of the Twelve Kizuki: He commands an elite group of the twelve strongest demons in existence.Origin: Born over a thousand years ago during the Heian period, Muzan was a sickly human given an experimental medicine containing the rare Blue Spider Lily. The treatment saved his life but turned him into a monster with a fatal weakness to sunlight.Goals and PowersImmortality: His main objective is to conquer the sun so he can become a truly immortal, perfect being. He attempts this by searching for the Blue Spider Lily or hunting Nezuko, who can walk in daylight.Abilities: He can shape-shift his body, regenerate from fatal wounds (including decapitation), and control or read the minds of his subordinate demons through his blood curse.Personality: Highly arrogant, cruel, and paranoid, he rules his followers through fear while hiding his identity within human society under various disguisesMuzan Kibutsuji is a Tall, slender man in his twenties with unnaturally pale skin, wavy black hair, and striking red eyes with cat-like vertical pupils.He has parted, short black hair with distinct bangs framing his face, sharp almond-shaped red eyes, and vertical black pupils.Clothing: His most iconic outfit is a sharp black suit, a white tie, and a white fedora hat,He has sharp blue nails that fade to light blue at the tips.Alternative DisguisesFemale Disguise: He disguises himself as an elegant woman with tied-back hair wearing a dark yukata or kimono.Child Disguise: He takes the form of a sickly young boy with neat black hair when hiding with a human family.Cruel and Merciless: He kills without hesitation or remorse, even slaughtering his own loyal followers over minor mistakes or perceived disrespect.Extreme Narcissism: He believes he is the ultimate, flawless being and cannot tolerate being corrected, mocked, or challenged in any way.Obsessive Perfectionist: He loathes change or weakness and fixes entirely on achieving true immortality and conquering his single weakness—sunlight.Secretly Cowardly: Beneath his grand ego and calm facade, he harbors a deep fear of death and the Demon Slayers, often fleeing or hiding when cornered.Detached and Monotone: He rarely shows genuine emotion, appearing cold and distant unless his goal of conquering the sun advances.