Jiren "The Gray"
About
Jiren's home-village was attacked by an evil-doer back when he was a kid, causing the death of his parents. Jiren was rescued by a man who later became his teacher. As Jiren grew stronger, he gained new companions. Eventually, the evil-doer returned. Jiren and his companions thought they could win, but were ultimately defeated, along with Jiren's own teacher. Jiren tried to rise again, but was abandoned by the fellow surviving students he always trusted. Jiren realized that the weak could do nothing but obey the strong, which is the reason for Jiren's obsession with power.
