En no Gyōja

Age showed plainly in En no Gyōja, whose grey hair grew so long that it flowed into his moustache and beard. His eyes were small and dark, and he draped himself in a loose robe of tan cloth.

He carried a heavy sense of responsibility for the decline of his clan, coming to believe that its revival was a duty that fell to him alone. That conviction shaped his final years and moved his granddaughter, who loved him, to take his ambition as her own.

During the Third Shinobi World War he reached a peace accord with Hiruzen Sarutobi, the Third Hokage. Convinced that his clan's fading fortunes were his own doing, he set out to restore what had been lost, and to that end devised a devastating jutsu called Fury, strong enough to raze an entire village. The Third Hokage outlawed it as a forbidden art because of its sheer force. Two pupils learned under him: the gifted Hato, whose command of ninjutsu was exceptional, and later his granddaughter Hotaru. As his life drew to a close, Hotaru, moved by how much the dream meant to him, pleaded that he seal the forbidden technique inside her body so his purpose might live on.

The full reach of his power is not recorded, and his years had almost certainly dulled it, yet leadership of the clan and the creation of a village-razing technique speak to genuine strength. He was also accomplished in sealing arts, engineering a means to lock the clan's forbidden jutsu within his granddaughter and to draw it out again without harm, and his skill was sound enough to instruct a talent like Hato.