Sharingan

The is a Kekkei Genkai, which appears in some members of the Uchiha clan of Konohagakure. Some think that it was derived from the Byakugan many years ago. It allows the user to comprehend the attack of an opponent almost before the attacker knows what attack they are making. The Sharingan also allows the user to see the flow of chakra within a person, but to a lesser extent than the Byakugan.

Stages
When the Sharingan is first activated by a user, it has a different number of tomoe around a central pupil, varing among the users. The wielder of the Sharingan, through continued use, evolves the Sharingan which involves gaining tomoe. The maximum number of tomoe in a conventional Sharingan is three. When the user gets three tomoe in each, he becomes able to predict all movement from his opponent, although he might not be able to keep up with him. The only level up from there is the Mangekyo Sharingan, which is said to be gained by the loss of someone exceptionally close to you, preferably by your own hands.

Origins
It is rumored that the Sharingan originated from the Byakugan, though it has a different set of abilities.

ZAILTSAA MALNUUDAA XAXAXAXAXAXAXAXA SHARINGAN CH GEH SHIG HIHIIIHIHIHI

this jutsu can only be done by Madara, as it needs buttload of chakra, Madara as he has eternal sharingan i.e, lootts of chakra

Receiving the Sharingan
Unlike the Byakugan, the Sharingan does not automatically appear from birth in a user; instead, the user has to awaken it. After this first appearance, the user can then call up the Sharingan any time he or she pleases. Due to its unique nature, however, Kakashi's Sharingan cannot be deactivated, and thus he usually covers it to conserve chakra. The power of the Sharingan is judged through the number of tomoe in the eye, known as the "tomoe seal". It is not unheard of for a Sharingan user to have different numbers of tomoe in each eye. For example, while Sasuke's Sharingan initially had one tomoe in each eye, his second random activation had revealed his Sharingan had evolved slightly, resulting in two tomoe in one eye, and one in the other. Upon his first regular activation of it, it had evolved to two tomoe in each eye. He evolved it to three in each eye during his battle with Naruto at the Valley of the End. A fully-matured Sharingan has three tomoe in each eye.

Transplanting the Sharingan
It is possible to transplant Sharingan eyes from one person to another, as occurred with Kakashi and his deceased comrade Obito Uchiha. However, transplanted eyes do not work as well in a non-Uchiha body, causing more strain on the user, as is the case with Kakashi (extended use of his Sharingan will cause him to collapse). Uchiha clan members are not burdened with this weakness; while activation of the Sharingan does consume chakra, the drain is so small as to be insignificant. Itachi in particular seems to have no trouble keeping his Sharingan activated near-constantly.

Transplanting the Sharingan eyes from a living or deceased Uchiha is the only way to avoid the loss of sight over time from the Mangekyo Sharingan.

Known Shinobi who Possess the Sharingan
Shinobi who currently possess the Sharingan include Sasuke Uchiha, Kakashi Hatake, and Madara Uchiha. Kakashi's eye was given to him by Obito Uchiha, one of his teammates in his original three-man ninja team.


 * Sasuke Uchiha
 * Kakashi Hatake (left-eye only, presumed deceased)
 * Obito Uchiha (Deceased)
 * Itachi Uchiha (Deceased)
 * Madara Uchiha (Unique Form, heightened by taking the eyes of his brother)
 * Izuna Uchiha (Deceased)