Why does Majin Buu not appear in this universe? Our heroes have changed events in the past so that things on Earth was not at all like their own world. We don't know how it affects the coming of Majin Buu, but here's probably why he hasn't come to this world yet...
Babidi tapped his foot impatiently. "You're late again, Darbura." Darbura wiped the sweat fom his forehead. "Huh. Sorry. Trouble in hell again."
Babidi snorted. "That Vegeta guy make trouble again?" Darbura sighed. "He's a real troublemaker. Today he incited another riot again. Nearly destroyed my capital, and blew up my palace. This is gonna take forever to repair." 'And if I'm not careful, he'll take over Hell one day,' Darbura thought silently to himself.
"He would be very useful to us," Babidi said thoughtfully. "If he's as strong as you make him out to be, we should be able to use his energy to free Majin Buu by now."
Darbura snorted. "He's useful only if you can control him, which you can't. I've never met anybody with a stronger will than him. He's thoroughly evil, no mistake about that, but you can't enter his mind unless he lets you. Don't waste your time with him."
Babidi turned aroud to face him. "You're right. If the King of Hell can't control him, who can?" The old shrivelled face smiled, with an amused and cruel glint in his eyes. 'Is that fear I sense from you, Darbura?' Babidi thought. This weakling will not keep his throne for long, he could foresee that. A pity this Vegeta is so uncontrollable, or else he could have just used his power to free Majin Buu instead of doing the tedious job of going from planet to planet just to collect enough energy to free it. 'But if you can't control it, it's of no use to you,' Babidi dismissed Vegeta with this thought.
"Come on. We have to find another planet for energy, or we'll never get Majin Buu freed," he said to Darbura.
Darbura silently sighed in relief. 'If Vegeta's controlled by Babidi, he'll overthrow me in no time,' he thought. 'When we've resurrected Majin Buu, I'll get rid of the tiresome old demon Babidi and use Majin Buu to fight Vegeta.' For now he'll just have to bear with Babidi, but Darbura is just biding his time. Or so he thought.
"Where to now?" he asked Babidi.
"We're moving away from this galaxy. There's nothing of interest so far. We'll be going to a neighbouring galaxy. Let's hope we'll get something useful there." Babidi had turned away from him again. He knew what the King of Hell was thinking. So stupid of him to think he could control Majin Buu by himself. 'Well, Darbura,' he chuckled to himself, when we free Majin Buu, maybe I'll let you live - if you'll be my slave forever.'
"Right." Darbura manned their spaceship and they flew away in seach of new energy, leaving Earth untouched for the time being, and Vegeta slowly taking over as ruler of Hell. And the last Prince of Saiyajins had never been happier.
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Next: The Bodyguard - Tenshinhan's Story
This omake wouldn't affect the flow of this fic - Babidi missed Earth, he's not likely to return there or free Majin Buu soon, if ever. As for Vegeta, he's about as happy as any Saiyajin could be; killing and conquering and controlling souls in hell, and he never knew what he missed in not being with Bulma.