One idea could be a crossover with the Dragon Ball Super universe. Kid Buu could encounter new and powerful foes like Jiren. Their fight would be chaotic and destructive, with Kid Buu's unpredictable nature causing all sorts of mayhem. Another idea is a crossover with the Naruto universe. Picture Kid Buu facing off against Naruto. Naruto's positive energy and willpower could be a contrast to Kid Buu's pure evil. He might try to reason with Kid Buu at first, but when that fails, a huge battle would ensue. And a third idea could be a crossover with the One Piece world. Kid Buu might land on the Grand Line and start causing trouble for the Straw Hat Pirates. Luffy would surely step up to protect his crew and the islands they visit from Kid Buu's rampage.
To start a Kid Buu crossover fanfiction, begin by brainstorming the crossovers that would make the most sense or be the most exciting. Let's say you choose the Star Wars universe. You should establish the rules of the crossover early on. How does Kid Buu's energy interact with the Force? Then, create a hook. It could be something like Kid Buu being drawn to the dark side of the Force. Now, introduce the Star Wars characters. Luke Skywalker might sense Kid Buu's presence and be determined to stop him. You can then start developing the plot by thinking about what Kid Buu wants in this new universe and how the Star Wars characters will oppose him.
One possible fanfiction could involve Naruto being transported to the Dragon Ball universe where he meets Female Majin Buu. Maybe they start as adversaries at first. Naruto, with his ninja skills, tries to fight her. But then they realize they have some common ground in their love for food. And they could end up teaming up against a greater threat in the Dragon Ball world.
The Naruto - Kid Buu fusion in fanfiction could be depicted as a being with a unique fashion sense. Since Naruto often wears orange and Kid Buu is mostly pink, the fused form might have a combination of those colors in its clothing or body markings. In terms of abilities, it could be shown as having the speed of Naruto when he uses his chakra to enhance his movement, combined with Kid Buu's ability to transform parts of his body into weapons. For example, the fused form could create Rasengan - like attacks from its hands which are also able to stretch like Kid Buu's arms.
In a fanfiction where Naruto fuses with Kid Buu, it could result in a very powerful and unpredictable being. Naruto's positive energy and strong will might conflict with Kid Buu's chaotic and destructive nature at first. But perhaps over time, Naruto could influence the fused form to use its power for good. For example, the fused being might have Naruto's skills like the Rasengan combined with Kid Buu's ability to regenerate and his raw power. It could also lead to some really interesting battles against other powerful characters in the Naruto and Dragon Ball universes combined.
A crossover with Naruto might be cool too. Picture Majin Buu in the Hidden Leaf Village. His presence would disrupt the balance of power. Maybe he'd be attracted to all the chakra and start absorbing it, leading to an all - out battle with the ninja.
Kid Buu is a very powerful and chaotic villain in Dragon Ball FighterZ. In the story, he is extremely destructive. He has a very simple and brutal nature, just wanting to cause chaos and destruction everywhere. His power level is off the charts, and he gives the Z - fighters a really tough time.
One key event is Kid Buu's destruction of many planets early on. Another is when Goku and Vegeta fuse to try and take on Kid Buu. Also, the moment when the Z - fighters come up with a final plan to defeat him is important.
Begin by brainstorming unique scenarios. If it's a crossover with the Marvel Universe, consider how Majin Buu would interact with the different heroes and villains. You could start with a simple concept like Buu being summoned to Earth - 616 by a villain who wants to use his power, but then things go wrong as Buu has his own ideas and starts causing destruction across the Marvel world. Outline your story, develop your characters, and then start writing the actual fanfiction.