Uub is a character trained by Goku who was Kid Buu reincarnated. He was taught by Goku and eventually surpassed him. Uub is now stronger than Kaio-ken times 5 Ultra Super Saiyan 3 Goku without even transforming! He also can use Kaio-ken times 5,000 to raise his power even further! He knows almost all of Goku's techniques.