In this form Buu enjoys an immense increase in power, as the evil within him has almost completely suppressed the good, and he can be considered a fusion character, for the separate Buus became two distinct entities. Both his height and musculature increase, with his eyes turning full black, save for the irises which are in turn red and white. The gloves previous Buus once wore are eliminated and replaced with black armbands, complimented by a new set of boots that are black and gripped.

He is easily irritated and impatient, entertaining himself by constantly cracking his neck with an insatiable desire to prove himself as the strongest fighter in existence. He first battles Gotenks, who is on even terms with him at Super Saiyan 3. Gotenks eventually defuses, but before Super Buu can press his advantage he is attacked by Gohan. Overwhelmed, Buu successfully schemes to absorb the power of Gotenks and steal the mind of Piccolo.