Trunks briefly fights both villains alone before the reinforcements arrive. Essential Trivia
Goku brings the Mafūba (Evil Containment Wave) jar to seal Zamasu, but the time machine and the jar are damaged shortly after their arrival. Bulma task Trunks with repairing the jar using super glue. Dragon Ball Super Episode 63
Before Goku and Vegeta arrive, Future Trunks and Mai attempt to take down the villains themselves. Mai tries to assassinate Black with a specialized bullet, and Trunks holds them off until help arrives, sustaining critical injuries. Trunks briefly fights both villains alone before the