Sharingan

The Sharingan is a genetic eye technique that naturally occurs in members of the Uchiha clan. It is not immediately present from birth, and first activates in a stressful situation in battle; after this occurrence, the user may utilize the Sharingan freely. When first acquired, the Sharingan has only one tomoe, and as its power increases, two additional tomoe will eventually appear. Kakashi Hatake possesses a single, transplanted Sharingan in his left eye that he received from his teammate, Obito Uchiha. Because he is not a member of the Uchiha clan, Kakashi’s Sharingan is always active and he expends chakra rapidly when using it, forcing him to cover it up when not in combat and needing extended rest after long battles. Members of the Uchiha clan expend a negligible amount of chakra when using the Sharingan; Akatsuki member Itachi Uchiha keeps his Sharingan activated constantly.

Over the course of its development, the Sharingan will grant the user three unique abilities. It is most famous in the Naruto world for its ability to memorize and replicate any movement it has seen, allowing the user to use an opponent’s jutsu against them. The Sharingan’s second ability grants the user increased clarity of perception, allowing them to track and predict the movements and actions of fast-moving objects. This also allows the user to easily recognize genjutsu and different forms of chakra. Its final ability is a brand of hypnosis that suggests actions and thoughts to the opponent, acting as an effective way to produce genjutsu or implant memories in another person.