How to Get Super Saiyan 4 in "Dragon Ball Z: Budokai 3"by Michael O. SmathersUpdated September 22, 2017
In "Dragon Ball Z: Budokai 3," you can travel around the world as the Dragon Ball Z fighters and participate in the storyline battles of the show. Throughout the mode, you can unlock the Super Saiyan transformations as skills to use in battle and give you an edge over your opponent. Super Saiyan 4, the most powerful form, is only accessible through Goku and Vegeta.
Play once through Dragon Universe, the game's story mode, as Goku.
Repeat Dragon Universe, and defeat Kid Buu with the Super Spirit Bomb. The Super Spirit Bomb is only usable when Goku is in Base Form or using the Kaioken x 10 power-up. To perform this move, enter Hyper Mode with "L2" and press "L2" again. If your attack connects, Goku will perform the Super Spirit Bomb. It requires five Ki Gauges.
Travel to the small cluster of islands near the red dot on the map. Land when you see the "???" label appear. You will find the Super Saiyan 4 capsule.
Begin Dragon Universe mode with Vegeta.
Play until you reach the Majin Buu saga map. When Vegeta is resurrected from the fight with Fat Buu, fly to Muscle Tower on the frozen island instead of to the next marker.
Land and talk to the Supreme Kai.
Fly to the marker on the map, and fight Super Buu.
Fly over the islands to the south until Vegeta speaks in a brief scene.
Go to the next marker to fight Broly.
Go to Baba's Palace after the battle, land in the nearby "Plains" area and travel to West City after the conversation with Bulma. You will receive the Super Saiyan 4 transformation for Vegeta.