Outer Path

The is the ability granted to the wielder of the Rinnegan to revive the dead. This ability was used by Nagato through the King of Hell.

Overview
Said to live outside the realm of life and death, Nagato could use the Outer Path: Samsara of Heavenly Life Technique to revive people that he recently killed. The souls of these people would be temporarily stored in the King of Hell. During the Fourth Shinobi World War, Kabuto Yakushi made note of how he could have Nagato kill the jinchūriki temporarily, store their souls in the King of Hell and then revive them at a later time.

Trivia

 * , derived from the Sanskrit Tīrthika, refers to any doctrine which "treads the outer path" to enlightenment. This is opposed to the teachings of orthodox Buddhism (the "inner path"), and is thus considered misguided and heretical.