In the last episode of Dragon Ball Super, Goku battled Black and Trunks time machine was destroyed, but luckily, Bulma had a backup time machine from that time Cell came to the past.
Now that the team has decided to use Cell’s time machine they have some time to train, have fun, and/or try to figure out who Black is before Bulma fixes it. Goku goes off to King Kai’s place to train, while Whis and Beerus lay back waiting for dinner and thinks about who Black could be, Vegeta goes into the gravity chamber for his own private training.
Back in the future black mimics Goku’s movement from the last battle they had. He realizes that Goku movements suit his body better. I guess Black will commence his very own training.
Things get a little weird when Future Trunks grabs young Mai’s hand and starts to reminisce about her Future Mai. Mai then asks Trunks, “how is her future self doing”, he was hesitant at first but later explained. Trunk tells Mai that she was part of a resistance force with the goal to kill Black. While Trunks is explaining to Mai about her future self we find out what Black’s true intentions are. He wants to destroy all human beings because he feels that they are unnecessary to the universe.
Bulma goes to get started on the time machine and gives Krillin and Piccolo the responsibility of fixing the field that Black and Goku help mess up.
Goku comes back to Earth with the help of Instant Transmission because he was unable to train at King Kai’s place. He tells Trunks to try not to be so stressed out, you can’t stay like that forever and to basically do his best.