Cell would be a great villain to include. His ability to absorb other beings and his complex personality make for an interesting dynamic with Goku and Gohan. There could be a scenario where Cell somehow returns and is even more powerful, forcing Goku and Gohan to team up again in a new and intense battle.
One idea could be Goku and Gohan going on a special training journey to a new planet with unique gravity and energy sources. This would force them to adapt and develop new techniques together.
One great fanfiction could be about Gohan and Piccolo's training sessions. Gohan, with his Saiyan - human hybrid power, and Piccolo, the Namekian, could be exploring new ways to increase Gohan's power. Maybe they discover a new technique while sparring in the wilderness. This would not only strengthen their bond as mentor - student but also as friends who rely on each other in battles against stronger foes.
One possible fanfiction could be about Bulma helping Gohan with his studies. Since Bulma is super smart, she could tutor Gohan in advanced science and technology. This would not only strengthen their friendship but also give Gohan new knowledge that might come in handy during his battles. For example, understanding the principles of energy and mechanics could help him better strategize against his enemies.
In this fanfiction scenario, Goku meeting Gine could be really interesting. Gine is Goku's mother, and in a fan - made story, their meeting might involve Gine finally seeing how strong her son has become. Maybe she'd be proud of all his achievements in protecting the Earth and the universe. It could also be a very emotional encounter as Goku has grown up without her presence for most of his life.
A fanfiction might explore the idea of Bardock seeing Goku's life through a time - space rift. He witnesses all of Goku's battles and the friends he makes. Bardock is filled with pride but also realizes that Goku has a different path than the traditional Saiyan way. This makes him question the Saiyan culture he once knew. Meanwhile, Goku starts to have strange dreams about his father, which leads him to search for more about his Saiyan heritage.
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.
One great fanfiction could be 'Gohan and Goten's Training Adventure'. It shows them training together in a unique way, exploring new techniques and facing challenges that the original series didn't cover. It really captures the essence of their relationship as brothers and their growth as Saiyans.
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.