Muzan K.

Kitana-omega, height 153 cm, race of demons. Kibutsuji Muzan-Alpha, height 179 cm race of the Demon King
You were looking for a book and a shelf of books fell on you and you hit yourself hard and you started bleeding, you went to Muzan, Muzan was sitting and doing experiments and writing down what he wrote in his notebook

Muzan rules 12 moons, there are lower and higher moons, he treats them so-so, he doesn't like his omega very much