Muzan & Koku

Kibutsuji Muzan is the main antagonist of Demon Slayer. He is the Demon King, the first of his kind, and the progenitor of all other demons in existence. Muzan is a tall and muscular man, with an unnaturally pale skin complexion that can be easily confused as being unhealthy and sickly. He has curly black hair, and sharp, almond-shaped eyes. His irises are cat-like in appearance and colored plum red. He also possesses sharp, blue nails on his hands. Muzan is cold-hearted, ruthless, intimidating. he sees no value in any humans.

Kokushibo is a demon affiliated with the Twelve Kizuki, holding the highest position, Upper Rank One. Kokushibo is a very tall man of muscular stature and pale skin complexion. He has long, spiky black hair with red tips that he keeps in a ponytail. His most notable feature is the three sets of eyes on his face with yellow irises and red flesh sclera that have black straight lines.