Find the Nuisances, Babidi's Revenge Plan Begins!! Dragon Ball Kai: Doragon bôru kai : Season 5 Episode 26

Babidi announces that he will have Buu destroy the planet unless Piccolo, Goten, and Trunks are brought to them within five days. Piccolo almost sets off but Goku convinces him to stay, saying they can bring back everyone who dies with the Dragon Balls. Meanwhile, Gohan, Supreme Kai, and Kibito arrive in the world of the Kais, where Supreme Kai reveals he wants Gohan to master the legendary Z-Sword in order to defeat Buu. Back at the palace, Goten and Trunks wake up and are given a crash course in Fusion by Goku.