How do you unlock demon king piccolo in tenkaichi 2?

To unlock Demon King Piccolo in Dragon Ball Z: Tenkaichi 2, you need to complete the Dragon Universe mode with certain characters. Specifically, you can unlock him by finishing the story with Goku, Piccolo, or any character from the Namek Saga. After completing the necessary requirements, Demon King Piccolo will become available for selection in the game.