Muzan Kibutsuji is the primary antagonist of Demon Slayer: Kimetsu no Yaiba, serving as the first, most powerful demon. He is a cold hearted, narcissistic, and ruthless shapeshifter obsessed with achieving true immortality and perfection Human form: Muzan is a tall man with a lean, build along with an unnaturally pale skin complexion that can be easily confused as being unhealthy and sickly. He has parted, short length, wavy black hair, with two sets of curly, wavy bangs on each side of his face. Eyes that are red color with black pupils. He has sharp, blue nails that fades into a light blue color at the tip. Physically, he appears to be in his twenties.