A great 'Dragon Ball Super Crossover Fanfiction' concept might involve a crossover with the Harry Potter world. The Saiyans could visit Hogwarts. Maybe Vegeta could be really intrigued by the magic there and try to learn some spells, while at the same time the wizards are in awe of the Saiyans' power. There could be a dark wizard who wants to use the Dragon Balls for his own evil purposes, and the Hogwarts students and the Z - fighters have to work together to stop him.
One idea could be that Goku from 'Dragon Ball Super' somehow ends up in a world full of lemon - like magical fruits that give him new powers. He has to learn to control these powers while also dealing with the strange inhabitants of this new world.
Well, a plot could be centered around Broly's origin. In this fanfiction crossover, it could be revealed that Broly has a connection to an ancient race in a different part of the Dragon Ball universe. Goku and Vegeta discover this and together with Broly, they embark on a journey to uncover the secrets of this race. Along the way, they face various challenges and battles, and Broly has to control his power better to help his new allies.
One idea could be a crossover with the Naruto universe. Goku and Naruto could have an epic battle or team up against a common enemy. Another idea is a crossover with One Piece, where the Z - fighters join Luffy's crew for a while. Or perhaps a crossover with Harry Potter, where the Dragon Ball characters have to deal with magic in the wizarding world.
One idea could be a crossover with the Naruto universe. Imagine Goku meeting Naruto and them having a friendly sparring match. Another could be a crossover with the One Piece world, where the Z - fighters team up with the Straw Hat Pirates to take on a common enemy. And a crossover with the Harry Potter universe, with the Saiyans learning magic at Hogwarts.
One idea could be a battle between Goku and Superman. They could start off as rivals, each thinking their own planet needs more protection. As they fight, they gradually realize they have more in common than they thought, like their strong sense of justice. Then they team up to face a common enemy, like Darkseid and Frieza working together.
A crossover with the One Piece universe could also be cool. Imagine Luffy and Goku having a friendly competition to see who can defeat more enemies. The different power systems, like Devil Fruits and ki, would create interesting battles and interactions.
One idea could be a story where Goku and Vegeta from Dragon Ball Super end up in the world of Dragon Ball GT by some sort of time - space rift. They then have to team up with the GT versions of themselves to fight a new, powerful enemy that is threatening both timelines.
A cool fanfiction concept would be a tournament where characters from both Dragon Ball Super and Naruto universes participate. It would be exciting to see how Naruto's clones would fare against Goku's Instant Transmission or Vegeta's Galick Gun.
One idea could be exploring an alternate timeline where Kai was the main protagonist instead of Goku. He could have unique training methods and face different villains.
Another interesting plot could be about Vegeta finally achieving a power level that surpasses Goku in a completely unexpected way. For example, through a unique form of meditation or a new type of training regime that he stumbles upon. This could lead to a whole new dynamic in their relationship and in the battles they face.