Uchiha Madara

Madara Uchiha is a major antagonist of the series. He co-founded Konohagakure, alongside the Senju clan, as leader of the Uchiha clan and later, after his defection, Akatsuki. When first introduced, he poses as Tobi, Deidara's partner in Akatsuki.Before the era of ninja villages, Madara was the most gifted member of the Uchiha clan. Even by his clan's standards, Madara's chakra was unusually strong. He grew up in constant competition with his younger brother, Izuna Uchiha. In their efforts to surpass the other, each gained their own Mangekyō Sharingan. With the power of the Mangekyō the two brothers took control of the clan, with Madara acting as its leader. Under his leadership, the clan conquered all they came across. Because of the never-ending series of battles of the time, Madara eventually began to suffer from overuse of the Mangekyō Sharingan, leaving him blind. In order to regain his sight he took Izuna's eyes for himself, granting him an "eternal" Mangekyō Sharingan with which he led the Uchiha to prosperity. Madara insists Izuna consented to the act.