Gohan could become more of a leader. With the power of Super Saiyan 5, he would be one of the most powerful beings in the universe. Other Z - fighters might look to him for guidance and leadership. This could bring out a more assertive side of his personality. He would need to step up and make tough decisions for the greater good, which would shape his personality in a more authoritative way.
One idea could be Gohan in his Super Saiyan 4 form facing a new, powerful enemy from another dimension. He could struggle at first to control the raw power of this form while also trying to protect his friends and family. Maybe this new enemy has the ability to nullify the Saiyan's energy attacks, forcing Gohan to rely more on his martial arts skills that he learned from Piccolo.
In a fanfiction, Gohan as Super Saiyan 3 could be involved in a time - travel adventure. He travels back to a crucial point in Dragon Ball Z history and has to use his Super Saiyan 3 powers to change certain events. This could lead to a whole new timeline where things are different. For example, he might be able to prevent the destruction of Planet Namek or save some characters who originally died.
Family relationships are also a big theme. His relationship with Videl, his daughter Pan, and of course his father Goku. Fanfictions often explore how Gohan balances his family life with his role as a Z - Fighter. For example, there could be stories about how he teaches Pan about her Saiyan heritage while also dealing with threats to the Earth. There are also stories that focus on his relationship with Goku, like how Gohan continues to be inspired by his father or how they train together to face a new powerful enemy.
One idea could be Gohan struggling to control the new power of the Super Saiyan God. He might accidentally cause some destruction while training and then have to deal with the guilt and the fear of his power getting out of control.
In many Dragon Ball Super fanfictions, Gohan's character development can take various directions. Some fanfictions might focus on his return to his Saiyan warrior roots. For example, he could start training intensively again after realizing the threat to his family and the universe. This would involve him pushing his limits in combat and rediscovering his latent powers.
I'm not entirely sure as I haven't read it fully, but generally, it might involve new heroes and villains in the Dragon Ball universe, with epic battles and power - ups for the characters.
In fanfiction, Gohan's Super Saiyan 2 form might have different power levels. For example, some fanfics might make him much stronger than in the canon, able to defeat enemies with a single blow that would give him a tough fight in the original story. Also, his appearance in the form could be more detailed or different, like his hair being a different shade of gold.
In this fanfiction, Gohan and Videl could start training together in a new environment, like a hidden valley. They face challenges specific to this place, such as strange creatures and unique energy sources. As they train, their relationship deepens, and they learn more about each other's limits and potential. They also discover new power - up techniques that they can use in future battles.