Captain America could be a great ally. His sense of justice and leadership would mesh well with Gohan's own values. They could both lead a team into battle and inspire others with their courage.
Gohan's powers would be quite unique in the Marvel Universe. His Super Saiyan forms would give him a massive boost in power, far beyond what most normal Marvel characters can achieve without some sort of external boost. His Zenkai boosts, which increase his power after near - death experiences, could also be an interesting concept to introduce. And his martial arts skills, combined with his Saiyan instincts, would make him a very adaptable fighter against the various threats in the Marvel world. He could also potentially teach other heroes his fighting techniques.
One idea could be Gohan getting transported to the Marvel universe and teaming up with the Avengers. He could use his Saiyan powers to help them fight against Thanos. Maybe his energy blasts would be a new weapon against the powerful foes in the Marvel world.
A cool plot could be that Doctor Strange somehow accidentally opens a portal to the Dragon Ball universe and Gohan is the first one to come through. Gohan then has to help the Marvel heroes against a villain who is using magic in a way that is similar to the way Babidi did in Dragon Ball Z. He could teach them about Ki and how to sense it, which would give the Marvel heroes an edge. Also, Gohan could have a friendly sparring match with Captain America or Thor, which would be really interesting to see as they compare their different fighting styles.
Often in these fanfictions, the writers will play with the characters' personalities. Videl, known for her strong - willed nature, might be even more head - strong in a crossover. Gohan, on the other hand, could be more reserved or have to adapt to a new set of rules in the crossover world. Their interactions based on these adjusted personalities can lead to some really engaging storylines.
Common themes in Gohan crossover fanfiction include identity. Gohan may struggle with his identity as a Saiyan in a world full of non - Saiyan characters. Another theme is the search for a way home. If he gets stranded in a different universe, like in a crossover with Star Trek, he has to find a way to return to his own world. And of course, there's the theme of heroism. Gohan is often pitted against great threats in these crossovers and has to rise to the occasion to save the day, whether it's from a Kaiju in a Godzilla crossover or a dark wizard in a Harry Potter crossover.
A common pairing is Gohan and Bulma. Their relationship in fanfiction can be interesting as they are both highly intelligent in different ways. Bulma's scientific knowledge and Gohan's martial arts and Saiyan abilities can create a dynamic where they complement each other well.
Piccolo could be an interesting crossover character. He could be from a world where lemons have some sort of magical or spiritual significance. His relationship with Gohan in the original story would add depth to their interactions in this crossover. For example, Piccolo might be initially skeptical of the lemon - related things but eventually see their value when it comes to helping Gohan.
Definitely Superman. Superman's super strength and Gohan's Saiyan power would make for an interesting combination. They could have a friendly sparring match to test their limits. Another good character could be Ichigo from Bleach. Ichigo's sword - fighting skills combined with Gohan's martial arts and ki blasts would create some epic battle scenes.
Probably Natsu. They both have a strong sense of justice and are very powerful fighters. Natsu's fire - based attacks and Gohan's ki blasts could make for some amazing combined attacks in battle.