One idea could be that Goku and Naruto meet in a strange dimension. They initially mistake each other for an enemy but then realize they have a common goal, like saving both their worlds from a new powerful villain. Goku could teach Naruto some of his ki control techniques, and Naruto could show Goku some of his more unique jutsu.
Well, a cool plot might be that the Sage of Six Paths in Naruto has a connection to the Kais in Dragon Ball Z. This connection leads to a situation where Naruto and Goku have to work together to stop an ancient evil that threatens both universes. For example, the evil could be a powerful demon that feeds on both chakra and ki. They would have to combine their powers and the powers of their friends to stand a chance. Naruto could teach Goku some of his shadow clone jutsu, and Goku could show Naruto how to achieve Super Saiyan forms.
One idea could be that Naruto and Goku meet during a interdimensional rift. They decide to have a friendly spar, with Naruto using his shadow clones and Rasengan while Goku goes Super Saiyan. Another could be that the Akatsuki are after the Dragon Balls for some reason, and the Z - fighters team up with the ninja of Konoha to stop them.
One idea could be a crossover with the Naruto universe. Goku and Naruto could team up to fight a common enemy. Maybe they face an evil villain who has the power - stealing abilities like Cell and the ability to use powerful ninja jutsus. Another plot could be a crossover with One Piece, where Luffy and Goku have a friendly competition about who can eat more food and then end up having to work together to defeat a new threat at sea that has the strength of Saiyans and the deviousness of pirates.
Well, a cool plot for Dragon Ball Xenoverse Crossover Fanfiction could be a time - traveling crossover. Imagine characters from different anime universes being brought to the Dragon Ball Xenoverse timeline. For example, characters from Fullmetal Alchemist arrive in the Xenoverse. Edward could use his alchemy skills against the Dragon Ball villains, and Alphonse could have some really interesting interactions with the Dragon Ball characters, like Bulma or Master Roshi.
One idea could be that Broly is transported to an alternate universe where he teams up with Goku from a different timeline to fight a new, powerful enemy. They have to combine their unique fighting styles to stand a chance.
One idea could be a crossover with the Naruto universe. Imagine Goku and Naruto teaming up to fight a common enemy like a powerful, evil entity that combines the worst aspects of the Akatsuki and the Red Ribbon Army. They could learn from each other's fighting styles, with Naruto teaching Goku about chakra and Goku showing Naruto the power of ki.
A possible plot for the crossover fanfiction could be that Ruby discovers a way to travel to the Dragon Ball universe. There, she meets Goku and the others and learns about ki and the different power - ups. She then brings this knowledge back to Remnant and tries to teach her friends. At the same time, some of the Dragon Ball characters could be curious about Remnant and follow Ruby back. This leads to a series of adventures where they have to deal with both the Grimm and the power struggles in Remnant, all while trying to understand each other's worlds better.
One idea could be a crossover with the Naruto universe. The Saiyans could learn about chakra and how to use it, while the ninjas are amazed by the power of ki. Another could be a time - traveling plot where the Dragon Ball Heroes characters end up in the past of their own world and have to prevent a major catastrophe that changes the course of their history. Maybe a crossover with One Piece where they search for the One Piece together and face off against the powerful pirates and the Marines.
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 that Goku and Naruto meet during a universal tournament. Goku, being his usual self, is excited to fight strong opponents. Naruto, on the other hand, is intrigued by Goku's pure love for combat. They could team up against a powerful enemy from another dimension who threatens both their worlds.