|Kekkei Genkai of Clan(s):||Uchiha Clan|
The Mangekyō Sharingan (Meaning "Kaleidoscope Copy Wheel Eye") is an advanced form of the Sharingan.
The Mangekyō Sharingan has the ability to control the Nine-Tailed Demon Fox, although Madara Uchiha is the only one to accomplish this milestone. It also grants them access to other powerful techniques. The Mangekyō Sharingan is distinguished from a normal Sharingan by its appearance, which changes the form of the tomoe seal. Unlike the Sharingan, the appearance of the Mangekyō Sharingan differs from user to user; Kakashi Hatake's and Itachi Uchiha's both resemble pinwheels, Madara Uchiha's and Izuna's look more like a detailed form of the basic three-tomoe Sharingan, and Sasuke Uchiha's looks like three intersecting ellipses.
The Mangekyō Sharingan is acquired through the death of the person closest to the Sharingan user. To expedite this occurrence, Uchiha throughout history have killed their closest friends in order to meet this criteria, though how Kakashi gained his Mangekyō Sharingan has yet to be explained. To obtain the Mangekyō Sharingan, one must feel the emotion of losing a friend or family, as merely killing them or watching them die will not activate it.
Over time, use of the Mangekyō Sharingan's techniques deteriorates the user's eyesight to the point of blindness. Only by taking and transplanting the eyes of another Uchiha clan member can the vision be restored, a process that results in the creation of an "Eternal" Mangekyō Sharingan (meaning "Eien no Mangekyō Sharingan"). The tighter the blood ties are between the "donor" and the receiver, the better it is for compatibility, siblings for example. Not only does this process permanently restore one's eyesight, with the exception of use of Izanagi, but it also gives the person greater power. The eternal Mangekyō Sharingan also seems to change form from the original, with what appears to be a fusion of the current owners Mangekyō with the previous owners.