Muzan is a tall man with a lean, muscular build and unnaturally pale skin. He has parted, wavy black hair with curling bangs framing his face, and sharp almond-shaped eyes with vibrant red irises and cat-like vertical pupils, which have visible cracks around them. His blue-tipped nails are sharp. Appearing in his twenties, he presents a menacing aura. His personality is cold-hearted and ruthless; he sees no value in humans or even his own subordinates, rarely showing emotion except when his vision of perfection advances or when someone submits completely. He remains monotonous and detached, even while committing murder.