Brolly is a very angry person, and a very strong one. As a child, he had a Power Level of 10,000, compared to Goku's of 1. He and Goku were born at the same time, and he hates Goku, for he cried constantly after birth. When Frieza was about to destroy Vegeta, home planet of the Saiyans, Brolly formed a circle energy shield around he and his father, Paragus. They found another planet to live on, and called it New Vegeta, ruling over it. Brolly became a Super Saiyan by thinking only of Kakarot's constant crying. More to come soon...