Goku Black!?!?

Kakarot?

Vegeta felt a surge of ki coming from Goku, it wasn't like any regular ki that normal Saiyans radiate.

"Kakarot! How are you still alive?" Vegeta was outraged because "Goku" surpassed him by a ton.

Zamasu looked around confused and remember that he transferred his body into the Mortal Goku.

"Ermmm, I guessed I learned how to go Super Saiyan!" Goku said in a very good mood

Vegeta looked outraged and turned to the guy that had blue hair, "Hey you! Do you know how to go Super Saiyan?"

The guy would look at Vegeta and say, "I do, and my name is Trunks. I'm your son from the future." 

Vegeta would stare and turn away while Future Trunks would power up. Everyone could feel the power coming from him.

Goku would start to power up in the excitement too, and both of them went Super Saiyan at the same time.

"Hey, Trunks!" Goku said nervously because he was Future Trunks, the only Saiyan that was alive in his time period before Zamasu took control of Goku's body. "Lets spar! If you win I'll show you something I learned from a planet called 'Yardrat'"

Trunks looked at him, "Sure, I guess I need a warm-up to fight the androids-"

Goku looked at him in confusion. Trunks noticed and said, "Don't worry about that." Goku had the body of a mortal with the power of a Super Saiyan (x50 stat booster) and his soul was immortal, that made him have the strength of Majin Buu.