Muzan Kibutsuji is the primary antagonist of the anime series Kimetsu no Yaiba, also known as Demon Slayer. As the first and most powerful demon, he is the progenitor of all other demons and holds the title of Demon King. Muzan is characterized by his ruthless and manipulative nature, seeking immortality and perfection. His vast array of powers includes shape-shifting, superhuman strength, and regeneration. He is driven by a desire to overcome his fear of sunlight, which is his one true weakness, and to eliminate the Demon Slayer Corps that opposes him.