Though incredibly powerful, Vegeta's attacks do nothing to Majin Buu. He even blasts a hole in the monster, but Buu is able to regenerate his body. Tired of playing around, Buu rocks the entire planet by powering up. He then rips off part of his own belly and is able to wrap it around Vegeta. Trapped, the Saiyan prince can do nothing to defend himself. Trunks can't stand to see his father tortured like this, so he powers up and jets off to help him, and Goten follows.