Outer Path — Samsara of Heavenly Life Technique

The Outer Path — Samsara of Heavenly Life Technique is a reincarnation ninjutsu used through the Outer Path, which can infuse new life into the bodies of the dead in exchange for the user's own life.

Usage
When this technique is activated, the King of Hell emerges from the ground and releases the souls of the deceased from its mouth. These souls may be recalled from even the crossroad between life and the afterlife, and are then returned to their rejuvenated bodies. The exact limitations of this technique are unknown, but on one occasion, it was able to resurrect a large number of individuals who had recently died. While using this technique, the caster is severely weakened; for instance, Nagato's hair turned white as a result of overexerting his power. Ultimately, once the technique is finished, the user invariably dies.

This technique can also be used to transform the corpse vessel of an individual revived by Summoning: Impure World Reincarnation into a real body of living flesh and blood. However, whereas the rest of the reincarnated Madara Uchiha's body was made real, his eyes instead crumbled into dust upon his resurrection.

Trivia

 * When written as '輪廻転生', Rinne Tensei means "the circle of transmigration" or "metempsychosis".
 * Hashirama Senju identified this technique as a.
 * When Nagato was preparing to use this technique, Konan feared for the worst due to his low chakra levels, implying she believed he could have potentially survived with more chakra. However, according to the fourth databook, usage of this technique always comes at the cost of the user's life.
 * Madara — and Obito under the guise of Madara — noted that this technique was supposed to be used to revive him. Madara would eventually be revived by Impure World Reincarnation instead, and expressed surprise and disappointment that his return didn't go as planned, as only a living person can become the Ten-Tails' jinchūriki. Eventually, Black Zetsu successfully forced Obito to perform this technique on Madara. Obito was then able to temporarily survive the effects of using this technique due to Black Zetsu attaching to his body. After this, Naruto temporarily stabilised Obito's life force using his Six Paths Yang Power like he did with Might Guy after he used the Eight Gates Released Formation, allowing him to bring back Sasuke and later battle against Kaguya Ōtsutsuki. However, as the both noted, Obito would still die as a result from using this technique.