Rui

Lower Rank Five, the child demon who built himself a false family.

Rui is a demon who looks like a child and holds the position of Lower Rank Five. In life he was a sickly boy until Muzan turned him.

Quick Facts

Rank: Lower Rank Five

Facts from the source article.

Background

When his parents tried to kill him to atone for what he had become, he killed them in self-defence, and the shock wiped out his human memories. As a favoured member of the Twelve Kizuki he was allowed to use his blood to turn humans and demons into a stand-in family, whom he mistreats because of his twisted idea of family ties. Envy of the bond between the Kamado siblings breaks his composure, and Giyu kills him; at the end he remembers his parents and joins them in Hell.