Rinnegan

The Rinnegan is characterised by a ripple-like pattern over the eyeballs, with a light purple iris and sclera. It is said to be the most powerful of. It was admired as being able to bring forth all ninjutsu. The holder of these eyes can completely master all five basic nature transformations that form the basis of ninjutsu. It was said that in times when the world is in disorder, a person is sent down from the heavens to become either a "God of Creation" who will calm the world, or a "Destroyer" who reduce everything to nothing. It also allows the user to use all of the six paths techniques, as well as the seventh path - that is "beyond life and death".

The Six Paths of Pain were all reanimated corpses that Nagato gave the Rinnegan to through some unknown means. By doing so, Nagato could see each individual body's field of vision, coordinating the bodies with extremely precise planning. The animals summoned by the Animal Path also possessed the Rinnegan, so Nagato controlled and also shared a field of vision with them and the King of Hell. On its own, the Rinnegan allows the user to see chakra, including otherwise hidden barriers. It can also decipher more of the Sage of the Six Paths' tablet than the Sharingan and the Mangekyō Sharingan are able to.

The first person to possess the Rinnegan was the Sage of the Six Paths. Because of the Sage's mythical status, many people believed the Rinnegan was only a legend or a mutation. It later showed up in Nagato during his childhood. Tobi claims that he gave Nagato the Rinnegan, however this could have been used to maintain his disguise as when Madara was resurrected he believed Nagato was responsible. For this reason, he believes he is entitled to taking the Rinnegan from Nagato's body after his death. He implants one of Nagato's Rinnegan in his left socket, replacing the Sharingan he lost to blindness.

Through unknown means, Madara Uchiha managed to awaken the Rinnegan shortly before his death. In his battle as a reanimated corpse against the Alliance, his Eternal Mangekyō Sharingan transformed into the Rinnegan. Based on data collected over the years, Kabuto Yakushi and Orochimaru hypothesised that this is a natural evolution.

Trivia

 * In the anime, the Rinnegan was depicted as being multicoloured in its first few appearances. Once coloured manga illustrations of the Rinnegan were released, this was corrected.
 * In Naruto: Shippūden episode 203, a silhouette of the Sage of the Six Paths is shown. Here, the Sage's Rinnegan is shown to be red instead of the usual colour.
 * is the Japanese term for Samsara, the cycle of reincarnation or rebirth in several Indian religions. This is reflected in the names of all Six Paths of Pain, which share the names with Samsaric realms of reincarnation.