Well, it could be really exciting. Gohan has his Saiyan powers like super strength and flight. In the My Hero Academia world, he'd probably be seen as an extremely powerful hero. His fighting skills and his ability to sense danger would make him a top - tier hero. He might not even need a quirk, or his Saiyan powers could be considered some sort of super - quirk. He could also train the students at U.A. to become stronger.
Well, it could be really interesting. Gohan, with his Saiyan powers, would be quite a unique addition to the My Hero Academia world. In a harem situation, he might attract various female characters from MHA. Maybe his strong sense of justice and his power would make him a popular figure among them. He could potentially form relationships with characters like Ochaco, who has a kind heart and might be drawn to Gohan's good nature.
One storyline could be Gohan trying to find a way back to his own universe while helping the heroes in MHA. Another could be Gohan teaching Izuku Midoriya some of his more advanced combat techniques.
Gohan could fit in by being a transfer student. His Saiyan powers would be seen as a very unique 'quirk'. In the harem aspect, his kind heart would draw the attention of the female characters. For example, Mina would find his positive attitude infectious.
Gohan's powers are on a different scale. His super strength and speed are not like the typical quirks in My Hero Academia. In a fanfiction, his ki attacks could be something completely new to the world. Quirks like Bakugo's explosion quirk might seem less impressive next to Gohan's full - power kamehameha. But at the same time, quirks that manipulate elements could potentially interact with Gohan's ki in interesting ways. For instance, a water - based quirk could be used to enhance or counter Gohan's ki attacks depending on how it's used.
In a My Hero Academia fanfiction, Gohan could be seen as a hero from another dimension. His moral code, which is similar to the heroes in MHA, would make him a natural fit. He could also train the students in new ways of combat, using his martial arts skills combined with his Saiyan abilities.
There were a few novels that could be recommended, including Those Years Living in the Future World of Dragon Ball, If Dragon Ball, Latiz took Gohan away, and The Strongest Sun Gohan of Dragon Ball. These novels all used Gohan as the protagonist, telling his growth and adventures in the Dragon Ball world. These novels might satisfy your need for Gohan to be the protagonist.
In this fanfiction, Gohan might learn valuable life lessons from Grandpa Gohan. Maybe Grandpa Gohan would teach Gohan some old - fashioned martial arts techniques that have been forgotten over time.
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.
Piccolo might also be a savior. He has a soft spot for Gohan since they trained together. He could use his strategic mind and powerful attacks to outwit Raditz and rescue Gohan. Maybe he teams up with Goku for an even more epic rescue mission.