17 Years after the defeat of the android duo the Majin Buu of Future Trunks' timeline has awakened. Even after training for so much time Trunks was no match for Buu. Trunks knew that if he wanted to save the earth he would have to do that one thing that he despised since he saw Babidi's special ability. Knowing there was no other way Trunks went into a pure rage state and got turned into a majin by his request. Right after obtaining this state he overthrew Babidi killing him in the process and then he went after Buu. Trunks' chances of winning the fight were very slight even though this Majin Buu was alot weaker than the one in the present timeline, he could still regenerate. As Trunks knew that the only way to win this fight was to sacrifice himself and blast Majin Buu so that not even one atom of him remains. So Trunks powered up the Death Buu Chaser technique and he killed Majin Buu also draining all of his life energy in the process thus dying.