Broly (DBZ)

Broly was born with a power greater than most elite adult Saiyans, and is mentally unsettled as an adult, partially due to the crying of the infant Goku in the incubator next to him when they were born, partially because of traumatic events during his childhood (including nearly being executed for his power as well as Freeza's genocide) and partially because his power was so extreme. He eventually becomes the "Legendary Super Saiyan" told of in legends, with his destructive tendencies only being quelled by a special controlling device created by scientists for his father, Paragus.