B-26 HOW IS BUU DEFEATED?

Goku gathers ki for a super Genki Dama from the people of Namek and the people of earth. However, most of the people on earth were unwilling to give part of their ki to Goku, so it took persuasion from Mr. Satan for Goku to finally gather enough ki from the people of earth. Even though there was enough power in the Genki Dama, Goku lacked physical strength to make it destroy Buu, so a wish was made to Porunga to restore Goku's strength, and finally, Buu was destroyed.