Dumbass No More: Buu, for being as close to an Eldritch Abomination that Dragon Ball continuity would allow. This is notably the second time in the arc where this form fails because of stamina loss. In Resurrection 'F ' Frieza says that there were two beings that he was supposed to never mess with: To Vegito. He murdered or caused the deaths of nearly the entire cast, the entire human population, and blew up the Earth, the latter being something no villain had ever succeeded at prior.
Inexplicably Awesome: Unlike previous examples like Frieza or Cell, physical blows from even a weaker opponent will noticeably deform his body upon impact and even ki blasts will punch through him easily, it's just that he can reset it just as quickly. Expanded universe material like Xenoverse and Online have Mr. Gone Horribly Right: Buu's main strength in every form is that he has the consistency of old chewing gum with an incredible Healing Factor.
However, he doesn't have Super Toughness. It wouldn't make the slightest difference how many of you were here. In the original release, he was a monster created by the wizard Bibidi.
But far and away the most dangerous thing about him is that he has bottomless energy and stamina, including the ability to immediately heal up from anything short of disintegration.
Dragon Ball Majin Buu / Characters - TV Tropes
On the other, Super Buu was shown to possess knowledge that Fat Buu didn't, such as how to sense ki, so it's not implausible that his nature as a Superpowered Evil Side lets him access additional memories on top of additional power. That's not to say Kid Buu didn't have the desire to fight strong warriors, just that it no longer conflicted with his desire to destroy everything else. He more often than not uses his reality warping ability to turn people or objects into food.
Like Cell before him, Buu has two methods for doing this: Nothing short of complete destruction of his entire physical being will put him down. For whatever reason, Buu enjoys being hit by attacks, trusting in his Healing Factor to let him shrug off whatever damage anybody inflicts on him.
He can even teleport into the afterlife, killing you for good after he kills you the first time. In the anime, however, Super Buu's regeneration slows down as he gets his ass kicked over and over again by Vegito, to the point where he didn't even notice that he still had a hole in his chest until Vegito pointed it out.
This is especially true in later years were his backstory was retconned to make his true origin completely unknown, and make him more of a Eldritch Abomination.
Oh, good. The form in which Buu appears when Babidi releases him, much to everyone's surprise.