Obtained: Speak to Babidi and his minions in the Great West Desert Area during post game as Goku. You will need to complete the sub story Babidi’s Back!
Objective: Train with Babidi and his minions
Travel to the Great West Desert Area then head for the center of the area towards the sub story marker to locate Babidi and his minions. Interact with them to start a fight with Pui Pui and some grunts. Defeat them to start a second fight with Yakon. Beat him to complete the story.