Yeah, this is the far and away the more confusing and less logical aspect of Buu's nature. That said, I think sense can still (mostly) be made of it.ekrolo2 wrote:Boo's form mechanics kind of irk me despite the "he's magic!" thing. Grey Boo eats Fat Boo and that makes Super Boo... but taking Fat Boo out makes Kid Boo... Why?
Grey Buu and Pure Buu are the same "person", only manifesting in different ways. Inside of the Fat Buu we're initially introduced to, there are two "essences" so to speak: Buu and the Kaioshin. The Kaioshin are now dissolved, so they're part of Buu, but they now make up a distinct part of Buu's physical body, which is why he looks the way he does. The Kaioshin essence is the dominant one, which is why he can still be reasoned with, and why the good half expels the evil half, rather than the other way around.
When the Kaioshin-dominated half expels the evil essence from the body, it's not expelling a solid, physical manifestation. It's expelling the evil essence. This evil essence then manifests itself in a body that is a mirror image of the actual body. Think of it like Piccolo Daimao being a mirror image of the body he was expelled from, only more twisted because Buu is a crazy bubblegum genie.
Next, the evil body absorbs the good body, and then metamorphosizes. He looks more like the actual Buu's original physical body, because the actual Buu essence is now once again more in control (but still with the Kaioshin's essence giving him an upgrade, and hence he's taller and semi-rational). Though he's reabsorbed the Good Buu, he absorbed the actual body, and the actual body has not yet dissolved.
When Good Buu's body is removed from Evil Buu's, there are two things going on that are different from when Grey Buu emerged from Fat Buu:
1. Good Buu was the base expelling the unwanted part, whereas now it is Evil Buu as the base expelling the unwanted part.
2. Good Buu didn't expel a body, he expelled an essence that then manifested as a body. Evil Buu is expelling a body, rather than an essence that then needs to manifest as a body.
Still doesn't explain why Evil Buu changes physically when he loses the Kaioshin essence, but Good Buu doesn't change physically when he loses the Buu essence. But, oh well. Nothing's perfectly logical, especially when dealing with alien demon bubblegum genies in a gag manga, and that's the kind of shit I'm still on board for to begin with. Hence, even though this isn't a 100% airtight explanation, it does the job well enough for the story to coherently function (which, again, is a miracle considering the breadth of the material and the author's creative process), and I'm not about to lose sleep over it.