Mui

is the main antagonist that appears Naruto 5: Blood Prison. He is the of the prison castle Hōzukijō, and he is using the ultimate imprisonment technique to drain the prisoners of their powers.

Appearance
Mui has long black hair that goes beyond his shoulders. He wears some sort of suit with a brown belt and a silver buckle. He also wears goldish brown boots.

Abilities
Not much is known about Mui's abilities, but it is made shown that Mui has the ability to blast Naruto several feet back, knocking him into a wall. Mui also has the ability to prevent others from moulding chakra.

Trivia

 * His name means "inactivity".