Wow, that was surprisingly good.
Very good job man! I am a big fan of anime, and even though DBZ has been done 349873490 times, you at least did something new. As some have said before, yea i'm not sure that could ever happen, seeing as Buu can't turn people Majin, and you have to have an evil heart and all, it was a good idea nonetheless. The art was pretty damned good, although some points, like Gohan at the end didn't look quite right. I don't even need to say anything about the sound, because it's been said already. The music and lip sync were good though. I would also like to offer voice acting if you're interested. It would be a good idea for you to fix this up and release a new version. 5 for you to boost the score!