In such fanfictions, Goku might develop by becoming more of a mentor to Gohan. He could teach Gohan new fighting moves and also how to control his emotions better during battles.
In a Gohan x Goku fanfic, their relationship can be delved into by creating scenarios where they have to rely on each other completely. For example, if they are in a situation where Goku's strength and Gohan's intelligence are both required to escape. Their different personalities can also be highlighted. Goku's carefree nature contrasted with Gohan's more studious and responsible side. And of course, flashbacks to Gohan's childhood and how Goku's presence or absence affected him can add depth to their relationship.
One possible interaction is that Bardock could spar with Goku and Gohan. He'd test their limits and see how much they've learned about fighting. Another could be Bardock sharing stories of Planet Vegeta with them, which would be really interesting for Goku and Gohan to hear.
In the manga, Gohan never managed to defeat Goku. Their battles often ended with Goku coming out on top or the fight being interrupted for some reason.
Well, some fanfictions focus on Gohan and Goku's time - traveling adventures. They might go back in time to change certain events in the Dragon Ball universe. Also, there are fanfictions where they team up with other characters in unexpected ways. For example, they could form a team with villains who have a change of heart. These fanfictions often show how Gohan and Goku's different personalities interact in various situations.
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.
You can focus on their emotional bond. For example, show how Goku's pride in Gohan's growth and achievements affects their relationship. It could be about Gohan seeking Goku's approval and Goku being there to give it wholeheartedly.
In 'Goku x Gohan yaoi fanfic', one characteristic could be the exploration of their characters in a more intimate context. Since Goku is often seen as a powerful and somewhat naive hero, and Gohan as his intelligent and strong - willed son, the fanfic might play with their personalities in ways that show a different side of their bond. For example, it could show Goku being more tender towards Gohan in a romantic sense, and Gohan being more open about his feelings for Goku. However, this is a very different interpretation from the original series where their relationship is based on family and training. It also might include elements like how they interact in private, their secret moments together, and how they deal with the outside world's reaction to their relationship. This kind of fanfic can be controversial as it goes against the traditional view of their characters, but for some fans, it offers a new and unique way to explore the 'Dragon Ball' universe.
In the 'goku and gohan betrayed fanfiction', perhaps they are betrayed due to a misunderstanding. Say, Goku makes a deal with an unknown force to save the universe, but it's misconstrued as him allying with the enemy. Gohan, being associated with Goku, is also seen as a traitor. And this misunderstanding could be spread by a character with their own motives, like a power - hungry individual who wants to take over the Z - fighters' leadership.