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.
A really interesting plot could be that Broly trains Gohan in a parallel dimension where the rules of power are different. Gohan has to learn to adapt to this new environment while also dealing with Broly's tough training. This could lead to some really cool power - up moments for Gohan.
Well, the plot might involve Broly somehow getting stranded on Earth where Gohan lives. Gohan, being the kind - hearted Saiyan - human hybrid, decides to help Broly adapt. In the process, they train together. Gohan tries to teach Broly about control, while Broly shows Gohan new levels of power. Their friendship grows and they end up protecting Earth from other threats that come their way.
The fanfic might show that Broly, despite his usually aggressive nature, has a soft spot for Gohan's potential. He could see Gohan as a worthy successor to the Saiyan power. So, he trains Gohan with a kind of rough love. During the training, Gohan might struggle at first with Broly's intense regime. But as time passes, he starts to adapt and even surprises Broly with his growth. They could form an unlikely bond through this training process, which could be a central theme of the fanfic.
In a Broly x Gohan fanfiction, Gohan could develop a new understanding of power. Instead of just relying on his academic knowledge and some of his traditional training, he could learn from Broly that power can also be about pure instinct. Meanwhile, Broly could develop his mental faculties. Gohan might introduce Broly to things like meditation or mental focus exercises. As a result, Broly becomes less of a mindless brute when it comes to fighting and more of a thinking fighter, which would be a significant character development for him.
One reason could be the contrast between the characters. Broly is extremely powerful and somewhat of a wild card, while Gohan has his own unique power and personality. Their interactions in a fan - made story can be really interesting.
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.