The Energy Sphere is the 233rd chapter of the Dragon Ball manga.
Gohan and Kuririn see the bright sphere Vegeta uses to transform into a Great Ape. Sensing his dad is in trouble, Gohan heads back to the battlefield with Kuririn reluctantly following behind. After finishing his transformation, Vegeta easily pummels Goku until he is blinded by Goku's Solar Flare technique. With Vegeta distracted, Goku runs off to create a Spirit Bomb.