Yoku Oni

In this world, there are creatures that will do anything, no matter how violent, in order to fulfill their desires. They possess extraordinary powers and the people came to call them Yokuoni. To protect the people against the Yokuoni, Masato Jitsunashi has taken up the job to hunt them. Although he's a Yokuoni himself, he bears the Justice Greed—the desire to seek justice and sentence them by his own hands.

(Source: Kodansha)