Maybe the story could focus on a young Saiyan who is born with a rare power that no one in the previous generation had. He has to train hard to control it and prove himself to the older Saiyans. For example, his power could be related to time - control, a very different ability compared to the usual Saiyan strength and speed. This would lead to a whole new set of adventures and challenges as he tries to master it while also dealing with the expectations of being a Saiyan hero.
One idea could be the children of the Z - fighters facing a new, powerful and mysterious enemy from a different dimension. This enemy could have unique powers that the new generation has to figure out how to combat.
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.
One interesting plot could be a new villain emerging from a long - forgotten dimension. This villain has powers that are a mix of different techniques from all the universes in Dragon Ball. He starts causing chaos by stealing the energy of strong fighters to open a portal to an even more powerful realm.
Perhaps a fanfiction where a young Saiyan from a destroyed planet manages to find their way to the Xenoverse 2 world. This Saiyan has a different fighting style compared to the ones we know. They join the Time Patrol not just to save timelines but also to find a new home for their kind. Along the way, they face discrimination from some of the other races in the Xenoverse due to their Saiyan heritage, but they prove themselves worthy through their strength and determination.
Another interesting plot could be that the gamer aspect brings in virtual reality elements. The Z - fighters enter a virtual world where they have to fight enemies with different rules. This virtual world could have power - ups and obstacles that are based on video game concepts, like finding hidden keys to unlock new areas or defeating bosses to gain special abilities that they can then use in the real Dragon Ball Z world.
A plot could involve Bulma creating a new device that Goku needs to use in order to defeat an extremely powerful enemy. Goku has to learn how to operate this device with Bulma's guidance, and they face many obstacles along the way. This would show their cooperation and how their different skillsets complement each other. It could also lead to some comical moments as Goku tries to understand the complex technology. Another interesting plot could be that they are both transported to an alternate dimension where the rules of the Dragon Ball world are slightly different. They have to figure out how to adapt and find a way back home while also uncovering the secrets of this new dimension.
One idea could be Future Gohan training a new generation of fighters in a post - apocalyptic world. He could pass on his skills and knowledge, creating a new hope for the future. Another plot could involve him finding a way to travel back in time to prevent the events that led to his world's destruction. Maybe he discovers a hidden power within himself that he didn't know he had and uses it to fight against the remaining threats in his world.
One idea could be Gohan crossing over into the Naruto universe. He could team up with Naruto and use his Saiyan powers to fight against the Akatsuki. Another plot could be Gohan in the Harry Potter world, using his ki to defend Hogwarts from Voldemort. Or perhaps Gohan in the DC universe, fighting alongside Superman against a common enemy.
One idea could be an OC with a unique power that can nullify the energy of any attack, which throws off the Saiyans' fighting strategies. Another could be an OC who is a master of a long - forgotten martial art that gives them an edge in battles against the Z - fighters. Maybe an OC who has a connection to an ancient and powerful race that even the Kais don't know much about.
One idea could be a story where the Supreme Kai has to train under Goku to regain his lost powers. It would be interesting to see their different fighting styles and how Goku's positive energy affects the Supreme Kai.
One idea could be an OC with a unique ki ability that no one in the Dragon Ball Z universe has seen before. For example, the ability to transform into an energy form that can pass through solid objects. Another plot could involve an OC who is from a long - lost race in the Dragon Ball Z lore and has to find their place among the Saiyans, Namekians, etc. A third idea might be an OC who is a time - traveler and has to prevent a major catastrophe in the Dragon Ball Z timeline.