Super Dragon Ball Heroes (2018)

S1E1 Goku vs. Goku! A Super Battle Begins on Prison Planet!

During a training session with Whis and Beerus, Goku and Vegeta are suddenly interrupted by Future Mai, who reveals that Future Trunks has been taken captive. A mysterious individual named Fu appears, informing them that Trunks is confined on a location known as "Prison Planet," a battleground for warriors from various timelines, orchestrated by Fu's sinister experiment. Upon their arrival, they encounter an alternate Goku, dubbed "Xeno Goku," who shifts into Super Saiyan 4 and attacks. Goku counters with Super Saiyan Blue, only to discover an invisible barrier trapping them. Eventually, Fu vanishes, and the two Gokus decide to join forces to find a way out. Meanwhile, Fu watches over the planet, hinting at a darker plan involving a menacing Saiyan.