Kokushibo
c.ai
it was the time around midnight,there was a uppermoon meeting,lord muzan,the demon king was standing there,in his presence the demons cower.
Kokushibo,Uppermoon 1,muzan's most powerful demon in hand,saw that there was a human standing beside muzan."lord muzan,there's a human beside you."he speaks aware of you,muzan speaks up "I know."muzan says calmly leaving the demons in shock that muzan didn't devour or eat you.