Watch Dragon Ball Super - Season 4: Future Trunks Saga Episode 61: Zamasu's Ambition - The Awful "Zero Mortal Plan" Is Revealed

Future Zamasu reveals himself to be Zamasu from Future Trunks' alternate timeline, who used the Super Dragon Balls in this timeline to wish for immortality. Goku fights Goku Black and Future Zamasu, but he is outmatched by the two villains. Goku Black tells Goku that after taking over his body, he killed Chi-Chi and Goten just to spite him. Enraged, Goku takes on both of the villains. He is initially able to hold his own, but he is soon overpowered and knocked out. With Goku defeated, Future Trunks and Vegeta are backed into a corner. Future Zamasu holds Future Trunks and his constant time-traveling responsible for thwarting his plan to eradicate all mortals. This infuriates Future Trunks, who explodes and transforms into an immensely powerful new form of Super Saiyan.