Dragon Ball Z: Fusion Reborn

A janitor’s accidental blunder transforms him into Janemba, a plump yellow demon who spreads chaos across the afterlife. Goku has been spending his time in the afterlife competing in martial arts tournaments for the dead, ever since his sacrifice in the fight against Cell. When Janemba’s rampage catches his attention, Goku teams up with fellow fighter Pikkon to take on the monstrous threat. But after their first clash, Janemba undergoes another shocking change-shedding his bulky form and shifting into a leaner, sword-wielding version of himself, stronger than any foe Goku has ever faced. With help from his old rival Vegeta, who is also dead, Goku must stop Janemba before the demon tears apart the universe itself.