Question: is buu a bad guy?
Answer: "Demon Person Boo (Good)"), also known mainly as Majin Buu, is the result of the Innocent Buu using fission to split into good and evil halves. ... After the battle against the pure Majin Buu, Buu is referred to as Buu instead of Majin Buu and to the world he becomes Mr. Buu.