After defeating Cumber and freeing Future Trunks, the events on Prison Planet was revealed to be conducted by the mastermind of Hearts. While there, they are confronted by the Saiyan criminal Cumber. Following the Tournament of Power, Goku, Vegeta and Future Mai are informed by a mysterious figure named Fu that Future Trunks is being held captive on a world called the Prison Planet, which is under control of Frieza’s brother Cooler.
