In this kind of fanfiction, Goku might lose his family. For example, his friends and loved ones could be killed by a powerful new enemy. This would leave him in a state of deep despair and loneliness, and he would have to find a way to carry on without them.
One possibility is that Goku loses his reputation. Maybe he is framed for a crime he didn't commit. This would turn his friends against him, and he would have to prove his innocence while also dealing with the loss of trust from those he cares about. It would be a huge challenge for him as he's always been seen as a hero in the Dragon Ball Z universe.
Perhaps Goku loses his powers completely. He could be hit by a strange new technique that strips him of his Saiyan abilities. Without his powers, he'd have to rely on his wits and the skills he learned before becoming a super - powerful fighter. He might start training all over again from scratch, facing many difficulties along the way.
Goku may also grow in terms of his wisdom. Through experiencing such great loss, he would gain a deeper understanding of life and the value of things. He could then use this new - found wisdom to try and rebuild his life, even if it's not the same as it was before. He might start to mentor others in a more profound way, sharing his experiences and the lessons he learned from losing everything.
One possibility is that Gine could train Goku in some long - forgotten Saiyan techniques. Since she is his mother, she might know some unique skills that could make Goku even stronger.
Another thing that could occur is that he might accidentally create new threats. By interfering with the past, he could disrupt the natural flow of events and cause new villains to emerge or existing ones to become more powerful in different ways. It's a risky move going back in time, even in fanfiction.
In this fanfiction, they might have an epic sparring session. Adult Goku could teach Kid Goku some new techniques, like the Instant Transmission. It would be amazing to see how Kid Goku reacts to Goku's Super Saiyan forms.
In fanfiction, when Goku meets his parents, it could be an extremely emotional moment. His father, Bardock, was a fierce Saiyan warrior. Goku might learn more about his Saiyan heritage directly from his father. Maybe Bardock would be proud to see how strong Goku has become, despite being sent to Earth as a baby. And his mother, whose identity is not as well - known in the original series, could perhaps share some tender memories of Goku's early days on Planet Vegeta. It could also lead to Goku getting new powers or training techniques passed down from his parents.
When Gohan's class meets Goku in fanfiction, there are numerous possibilities. Goku could be invited to talk about his adventures across different planets. His tales of fighting powerful foes like Frieza and Cell would be fascinating to the students. Maybe he'd even bring out some of the Dragon Balls as a show - and - tell item. This would not only shock Gohan's classmates but also make them realize the vastness of the Dragon Ball universe. Goku could also interact with Gohan in a different way in front of his class, showing a more father - son relationship than what they usually see in the normal series.
A plot could involve Goku being transported to a future where all his friends are dead and the world is in ruins. The unknown circumstances that led to this and the feeling of helplessness could make him scared. He then has to figure out how to go back in time and prevent this future from happening, all while being afraid of what he might find out about how this came to be.
In some fanfictions, Goku and Raditz could form an unlikely alliance if they were faced with an even greater threat. For example, if a new and extremely powerful enemy emerged that threatened not just Earth but the entire Saiyan race. Raditz, who initially came to Earth with the intention of conquering it, might see the need to team up with Goku to save their home planet. Goku, being the good - hearted Saiyan he is, would be open to the idea if it meant protecting his loved ones.
One possible plot could be that Android 21, with her unique powers, teams up with Goku to face a new and powerful enemy. They might have to combine their strength and fighting techniques to defeat this foe.
He could die in battle. Maybe a new, extremely powerful villain emerges who has the ability to nullify Goku's powers or is just so strong that Goku's attacks have no effect. After a long and intense fight, Goku is defeated and dies.