Outer Path — Samsara of Heavenly Life Technique

By channelling his power through the King of Hell, the Rinnegan wielder can re-infuse new life force energy to the dead bodies of those who have died. With their rejuvenated bodies acting as an anchor, the individual souls are then able to leave even the crossroad between life and the afterlife, returning back to their physical vessels. The technique targets all the individuals killed, even those not necessarily killed by Nagato. This technique seemingly requires a massive amount of chakra, as Konan feared the worst for Nagato when he used it after having previously expended so much chakra. Nagato also became severely weakened, his hair became increasingly thinner and greyer as he performed the technique.

Influences
As with many of Nagato's techniques, it is influenced by Buddhist terminology. , 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.

Trivia

 * Tobi noted that this technique was originally meant to be used for his purposes, that being to revive Madara Uchiha. Indeed, when Madara was reincarnated by the Impure World Reincarnation, he first remarked that Nagato must have finally grown up, and was shocked when he was told that it was not this technique that had brought him back.