In a fanfiction, Future Gohan could potentially defeat Black Goku. Gohan has shown great power in the past, and if he were to tap into his hidden potential again, he might be able to overpower Black Goku. However, Black Goku is also extremely strong, so it would be a very tough fight.
Well, in a fanfiction scenario where Future Gohan takes on Black Goku, there are many factors to consider. Gohan's training and his experience in the future timeline could give him an edge. But Black Goku has the power of a Saiyan and the devious mind of Zamasu. If Gohan were to win, it might be through a combination of his martial arts skills and his ability to strategize. He could potentially find a weakness in Black Goku's fighting style. On the other hand, Black Goku could use his time - ring and his unique ki attacks to gain the upper hand. It would be a battle full of twists and turns.
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.
In the fanfiction, perhaps they team up to fight a common enemy. Goku's raw power combined with Gohan's strategic mind from the future battles could make them an unbeatable duo. They'd exchange blows and strategies, and their teamwork would be amazing to read about.
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 some fanfictions, Gohan and Goku might have a series of conversations that open up new levels of understanding between them. Gohan could share his thoughts and feelings about his life and future, and Goku would listen and offer his own insights. This kind of communication can really strengthen their bond.
I think Black Goku might have the upper hand. He has shown to be extremely powerful and has some unique abilities. His Saiyan body combined with Zamasu's knowledge makes him a formidable opponent.
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 many fanfictions, Goku's protectiveness of Gohan is shown through his constant presence. He might train Gohan more rigorously to make him stronger so he can defend himself. For example, in some stories, Goku takes Gohan to special training grounds that are hidden from the rest of the world. This not only protects Gohan from potential threats during the training but also hones his skills in a more secluded environment.
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.
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.
It could be Vegeta. Maybe in this fanfiction, his pride gets the better of him and he feels overshadowed by Goku and Gohan's power. So he fabricates some lies to make them look like traitors to the rest of the group.