>>281535644
It's a split timeline where Zamasu doesn't die to Beerus' Hakai because of the Time Ring. Zamasu travels a year into the future with the Time Ring, since the Super Dragon Balls had already been used to revive Earth in Universe 6. Zamasu uses the Super Dragon Balls to swap bodies with Goku, and then kills Goku, Goten and Chi-Chi and heads to Future Trunks' timeline.