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.
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.
Perhaps in the fanfiction, an evil version of Goku from an alternate timeline arrives. This impostor causes chaos and destruction, but everyone blames the real Goku. His family and friends are deceived by the look - alike. Goku tries to prove his innocence but no one will listen. He might have to find a way to expose the impostor and regain the trust of those he loves.
One possible plot could be Goku reminiscing about his past with Grandpa Gohan. Maybe he visits the place where they used to train together. He could find an old relic or something that Grandpa Gohan left for him, which triggers a flood of memories and emotions. This would be a heartwarming story about their relationship.
Perhaps in the fanfiction, Goku accidentally ends up in a different part of Otherworld where he stumbles upon Grandpa Gohan. Grandpa Gohan could then take Goku on a tour of Otherworld, showing him all the different areas and the souls there. They might encounter some old enemies or friends who have passed away. And along the way, Goku and Grandpa Gohan could strengthen their bond and Goku could grow as a character from the experience.
One of the characters who could betray Goku is Piccolo. Although they've been allies for a long time, in fanfiction, things can change. Perhaps an ancient evil force takes control of Piccolo's mind and makes him turn on Goku. Or it could be Krillin. He might be influenced by an outside force that convinces him Goku is becoming too dangerous. Also, don't forget about the Kais. If there's some sort of power imbalance or a threat they perceive from Goku, they might betray him to maintain the order of the universe in the fanfiction.
One possible interesting plot could be Gohan unlocking a new, unexpected power level during the Cell Games. For example, instead of just going Super Saiyan 2, he could access a form that combines the power of both Goku and his own latent abilities. This new form could have unique characteristics like different colored ki blasts or enhanced speed and strength that not only surprises Cell but also gives Gohan a whole new perspective on his power.
In this fanfiction, Bardock might be shocked to see how much Goku has grown and the family he has built. He could be proud of Goku for becoming such a strong and kind - hearted Saiyan. And when he meets Gohan, he might see the potential in him as well, maybe even offer some unique Saiyan training tips that are different from what Goku has taught Gohan.
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.
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 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.