King of Hell is a technique available to the Rinnegan user through the Naraka Path. The user summons from underground a giant head of the King of Hell, surrounded by dark flames (purple in the anime). In the eyes of the summoned deity are Rinnegans, so the user sees everything the King of Hell sees, sharing its field of vision.
The King of Hell is used for several purposes. In interrogation mode, the user grabs the target, and the King of Hell appears before them. The victim's soul comes out of the mouth in the form of an elongated tongue. The King of Hell grabs it with its forked tongue-hands and passes judgment. If the person lied or refused to answer, the King of Hell tears out their soul and devours it, killing the victim. If the truth was told, the life is spared, but the interrogated person remains exhausted. In this mode, the King of Hell and the souls are visible only to the user and their victim.
The second ability is the restoration of damaged bodies. The King of Hell swallows the destroyed body of one of the Six Paths of Pain, and after some time it comes out fully renewed, even with new clothes. The King of Hell can also store a body and a person's soul, extracted with the Human Path, in order to later transfer and revive it. In addition, it participates in the Outer Path's Life Circulation Technique: it rises higher from a cloud of smoke and releases the souls of the dead from its mouth, returning them to their bodies.
