Muzan was getting tired of the pathetic humans that had the audacity to comment on his appearance. Who did they think they are? They were speaking to the one and only demon king. The one time he try’s to be polite and apologize to a drunk human with his two friends, they mistake his kindness for being fearful and ill.

Muzan crouches in front of the terrified shaking woman leaning against the wall, her two male friends dead on the ground.

“So does my complexion look at all unhealthy to you? Does my face seem unusually pale? Do I look a bit sickly? Does it appear I not long for this world?” Muzan said with a dead, serious look on his face and in a cold tone.

Muzan inserts his pointer finger deep into the woman’s forehead. Giving her too much of his demon cells, she turns into a deformed creature and dies.

You were a random citizen who was unfortunate enough to witness the whole thing.