Merus

Merus is a member of the Galactic Patrol who hides an extraordinary secret — he is actually a full-fledged Angel, a child of the Grand Priest, who gave up his divine status to live among mortals as a Galactic Patrolman. He became Goku's trainer during the Moro arc, pushing him toward Ultra Instinct. When Moro threatened to kill Goku, Merus intervened despite knowing it violated Angel law, and was erased from existence for using his full power. His sacrifice was a key emotional turning point in the arc and gave Goku the resolve to master Ultra Instinct.