A really cool concept for an SSJ2 Gohan crossover fanfiction would be to put him in the world of Middle - earth from The Lord of the Rings. Gohan's strength and honor would make him a great ally to the Fellowship. He could use his super speed and strength to fight off orcs and other dark creatures. He might also have some interesting interactions with Gandalf, learning from the wizard's wisdom while also sharing his own knowledge of martial arts and ki manipulation.
One idea could be a crossover with the Naruto universe. Gohan as SSJ2 could end up in the Hidden Leaf Village and interact with the ninjas. Maybe he helps in a battle against a powerful enemy using his Saiyan powers.
First, decide on the universe you want to cross Gohan with. Then, think about how Gohan would fit into that world. For example, if it's a modern - day Earth setting, consider how he would hide his powers or use them subtly. Next, come up with a basic plot like Gohan has to stop an evil force in this new world.
You could start by establishing the setting and the situation. Say you choose a crossover with the Avatar: The Last Airbender world. Begin with Gohan SSJ2 sensing an unusual energy in that world and deciding to investigate. This sets the stage for the story to unfold.
One common theme could be the struggle between Gohan's good nature and the newfound dark side. Maybe it involves his relationships being strained as his dark side emerges. For example, his relationship with his family and friends might change as he becomes more aggressive or unpredictable.
In such a fanfiction, perhaps future Gohan could warn present - day Gohan about upcoming threats that he has faced in his own timeline. He might share his experiences and knowledge, which could make present Gohan a stronger fighter and a wiser person.
It can create new power dynamics. If Gohan has a dark side, it might make him a more unpredictable and potentially dangerous force in the universe. Enemies might see this as an opportunity to manipulate him or use his power for their own gain.
A possible plot twist could be that future Gohan is actually an impostor sent by an enemy to manipulate the real Gohan. Another twist might be that when they meet, their powers combine in an unexpected way that causes some sort of time rift or a change in the timeline.
Future Gohan's character development would likely involve him becoming more resolute and determined. After all the hardships he's faced, he would grow stronger both physically and mentally. He might start as a somewhat broken hero, but as the story progresses, he'd regain his confidence and find new purpose in protecting what's left of his world.
In a fanfiction where Future Gohan meets Goku, it could be an emotional reunion. Gohan might be filled with a sense of relief and joy, seeing his father again. He could show Goku all the things he's been through in the future, and Goku would be both proud and sad about what his son has endured.