Um, in the show I don't remember buu ever really using mouthblast. The only thing close to it is blowing air to destroy buildings. Usually he shoots a ball of energy into the ground and it expands quickly, or he unleashes energy from himself. Also in the episode where buu and evil buu fight they both use kamehameha on each other. I don't know why they would use this but they did. I know Buu is cheap enough as it is but I think in addition to mouthblast, buu should get one of his real attacks.