Rinnegan

The Rinnegan (輪廻眼, Literally meaning: Saṃsāra Eye) is reputed as the most exalted eye amongst the "Three Great Dōjutsu" the others being the Sharingan and the Byakugan. It is said that in times of disorder, one who wields the Rinnegan is sent down from the heavens to become either a "God of Creation" who will calm the world or a "Destroyer" who will reduce everything to nothingness. The Rinnegan is characterised by a ripple pattern that spreads over the eyeball.

Acquisition
The Rinnegan was first manifested by Hagoromo Ōtsutsuki in the Shinobi World, derived from the Rinne Sharingan wielded by his. It is suggested his Rinnegan was a kekkei mōra, and with it, he saved the world from the and created, the precursor to modern ninjutsu. In the anime, after experiencing the trauma of loss, Hagoromo awakened his Mangekyō Sharingan which almost instantaneously progressed to become Rinnegan. For his contributions to the world, Hagoromo became revered as the Sage of Six Paths, and both he and his eyes rose to mythological status over the centuries that followed; even when the Rinnegan was later proven to exist, it was regarded by some as merely a mutation.

The Rinnegan can typically be awakened by gaining Hagoromo's chakra either by reproducing it from combining the chakra of Hagoromo's sons, and, or by directly receiving chakra from Hagoromo himself. spent centuries attempting to manipulate the reincarnations of Indra and Asura into awakening the Rinnegan. It was not until the time of - Indra's reincarnation - that this was successful, when Madara infused himself with the DNA of  - Asura's reincarnation. However, Madara's Sharingan did not become Rinnegan until decades later, at the end of his natural lifespan; this also seemingly restored the eyesight lost from his use of Izanagi. When reincarnated Madara, he operated under a similar hypothesis that Sharingan can be evolved into Rinnegan through combination with Hashirama's DNA. To that end he successfully recreated the Rinnegan in Madara's reincarnated body, though these fake eyes did not have full access to the original's abilities.

's left Sharingan became a Rinnegan when Hagoromo's spirit gave half of his chakra to Sasuke. His Rinnegan contains six split between its first two ripples and retains all of the abilities of his Mangekyō Sharingan. If Sasuke overuses the power of his Rinnegan, the tomoe will disappear until it has fully recharged, a process which takes a considerable amount of time. During this time, he is unable to use the Rinnegan's full power and apparently cannot even activate the Mangekyō in his other eye.

Contrary to Madara and Sasuke's cases in needing Hagoromo's chakra, has Rinnegan in the palms of his hands. Initially, his Rinnegan are red, but they become purple (in the movie), or yellow (in the manga) after he absorbs. This also grants him a third Rinnegan on his forehead.

As with any dōjutsu, the Rinnegan can be transplanted into others. Prior to his death, Madara implanted both of his eyes into the young without the boy's knowledge, and he was able to make effective use of the Rinnegan throughout his life due to his Senju lineage. After Nagato's death, the Rinnegan were taken by, who implanted the left eye into himself and hid the other because he could not handle the power of both eyes at once. Madara later reclaimed both of his Rinnegan after he was revived and ultimately died with them.

Ryun Uchiha
Like his predecessor, Ryun was an exponentially powerful Uchiha shinobi who was capable of awakening the Mangekyō Sharingan and obtaining its "eternal" counterpart. After meeting an aging Madara in his youth, Ryun managed to gain access to Hashirama's DNA, which contained the power of Asura's chakra. Later, during a climatic battle with, Ryun subconsciously met with Hagoromo and learned to harness the unique chakra being born within himself, allowing him to awaken his own Rinnegan.

Abilities
The Rinnegan grants the wielder a wide range of abilities without any known chakra requirement to keep the eyes active. Certain abilities are only available to the original owner of the dōjutsu, but possession of even a single transplanted Rinnegan can grant overwhelming power. Rinnegan are able to see chakra, as well as its flow within the body and the activated tenketsu of the Eight Gates, but cannot see through obstructions such as s. One who possesses the Rinnegan can easily master any jutsu as well as all five nature transformations, create s into which they can transmit their chakra, fully decipher the written by Hagoromo, and counter the effects of the Infinite Tsukuyomi.

Possessing the Rinnegan grants the user a family of abilities collectively known as the Six Paths Technique: control over attractive and repulsive forces with the Deva Path; the ability to mechanize one's body with the Asura Path; soul extraction through the Human Path; the menagerie of summons available to the Animal Path; chakra absorption through the Preta Path; and access to the King of Hell through the Naraka Path. These abilities can be distributed to the Six Paths of Pain — six bodies embedded with black receivers, which the user can control remotely. A seventh ability, the Outer Path, is said to allow the user to preside over life and death, granting the ability to revive the dead. The user is also able to summon and control the Demonic Statue of the Outer Path, as well as manifest chakra chains to bind the tailed beasts. The dōjutsu also grants the user a shared field of vision with the Six Paths of Pain, the King of Hell, and the Animal Path's summons, all of which possess copies of the Rinnegan.

Certain Rinnegan abilities have only been demonstrated by single users: Madara can create corporeal shadows in the invisible world of Limbo, which is only visible to the Rinnegan; Sasuke's Rinnegan allows him to shift spaces within a certain range of himself, and create to other dimensions; Momoshiki is able to absorb any ninjutsu with his right Rinnegan and subsequently release it from his left, transform others into chakra-filled edibles, and use a space–time ninjutsu to travel to and from a separate dimension.

Sasuke’s Rinnegan had several sciences to it, and one of them was pattern recognition. It helped him analyse patterns inside codes, and by comparing them to similar patterns, decipher what was written. When put into use, one could take large amounts of information from a small amount of text.