Goku and Vegeta's training with Whis and Beerus is interrupted by the arrival of Future Mai, who tells them that Future Trunks has been captured. A mysterious figure emerges, introducing himself as Fu; he tells Goku, Vegeta and Mai that Future Trunks is trapped on a world called the "Prison Planet", a planet where warriors from alternate timelines and dimensions fight as part of an experiment conducted by Fu. The trio arrive on the planet and meet an alternate version of Goku called "Xeno Goku", who transforms into Super Saiyan 4 and attacks Goku, who reacts by transforming into Super Saiyan Blue. During the fight, Goku discovers that there is an invisible barrier around the Prison Planet that prevents them from escaping. Then Fu disappears, and the two Goku agree to work with each other to escape the planet. In the end, Fu observes the Prison Planet and tells a seemingly evil Saiyan that his time will come.

Towa restrained Xeno Goku, Xeno Vegeta, Xeno Trunks, and Xeno Pan in her artificial space using Cumber's dark ki, and proceeds to reveal Fu's nature as her creation using data from previous Dragon Ball fighters and villains. She explains that her plan is to make Fu as the new Demon King using Mechikabura's ki she stored in a dark energy orb upon his death. Xeno Goku manages to break free and attacks Towa, only to be blocked by Mira. Towa teleports Xeno Gohan and Xeno Goten into the space, both unconscious as their ki has been drained before, then teleports Mira and herself out as the space breaks, pulling all inside into something like a black hole. Meanwhile, Vegito in Super Saiyan Blue is fighting Fu in the front of Universe Tree and seemingly getting the upper hand.

Xeno Vegito outruns the energy wave before it dissipates, leaving the area around the Tree unscathed; he returns to find Fu holding the miniaturized form of the new universe created by the Tree. However, Fu is disappointed by his creation, as the new universe is flawed because Fu had to use his own demonic power to refuel the Tree rather than the pure energy of a normal universe. A furious Xeno Vegito attacks Fu, determined to stop him from doing anything else, and their battle resumes. Towa challenges Demigra, but his female companion takes her on instead, while Demigra uses a mystical technique known as "Time Labyrinth" to freeze both Xeno Vegito and Fu in time. Towa claims that Fu will be able to escape the frozen-time bubble, but Demigra is confident that he will not. On Beerus's planet in the Seventh Universe, Whis and Vados sense the creation of the flawed new universe. Meanwhile, in the new universe, Goku awakens alone, in a strange, empty version of West City.