Well, it could be about Bardock arriving on Namek before the Saiyans' destruction. Maybe he teams up with the Namekians against some common enemy. He could use his Saiyan strength and battle instincts to help protect the Namekian villages.
In a fanfic of Bardock arriving on Namek, he could land in the middle of a conflict between different Namekian tribes. Bardock, with his warrior skills, might get involved and try to bring peace. He may also find that the energy on Namek is different from what he's used to and has to adapt quickly. His arrival could also set off a chain of events that changes the future of both the Saiyans and the Namekians.
In the fanfic, Bardock might find a connection between the Saiyan and Namekian races that was previously unknown. There could be an ancient prophecy on Namek that mentions the Saiyans, and Bardock's arrival could be seen as the start of the fulfillment of that prophecy. This could lead to a whole new set of adventures and alliances for him.
In the fanfic, Bardock arriving on Namek could lead to a change in the power dynamics. He could train with the Namekians and learn their unique techniques. This new knowledge combined with his Saiyan strength would make him an even more formidable opponent. And perhaps, his presence could inspire the Namekians to be more proactive in defending themselves against external threats.
Perhaps the fanfic could revolve around Bardock's scientific exploration of other planets. As a brilliant scientist, he could be leading expeditions to study different ecosystems and civilizations. He might make a discovery that changes the Saiyans' view of the universe. For example, he could find a planet with a technology far more advanced than their own, which could either inspire them to learn and grow or make them feel threatened and trigger a war.
One idea could be that Bardock, after somehow escaping the destruction of Planet Vegeta, lands on Namek. He then meets a young Namekian who is curious about his Saiyan powers. Bardock could start training this Namekian, passing on some of his combat skills.
If Bardock arrives on Namek in the fanfic, it could also change the fate of the Dragon Balls. Instead of being just a tool for Frieza or the Z - fighters to use, Bardock could have a different vision for them. He might see them as a way to not only save Namek but also to restore the Saiyan race. This would open up a whole new set of plotlines and possibilities, as his motives would be different from the other characters who have interacted with the Dragon Balls in the original story.
The fanfic could be a story of their growth as characters. Bardock is known for his rough exterior but there could be a deeper side to him that Fasha discovers. Fasha herself might have her own insecurities or goals. The story could detail how they overcome their personal challenges while being there for each other. It could also include their interactions with other Saiyans and how they are perceived by the Saiyan community.
One possibility could be that it focuses on their first encounter. Maybe Bardock saves Gine from some sort of danger on their planet. This could be the start of a deep friendship or even a romantic relationship in the fanfic.
One possible plot could be Bardock's adventures before Goku was born. Maybe it could show how he dealt with the Saiyan politics and his growing concerns about Frieza's rule. This could set the stage for Goku's future battles as his son.
A fanfic about Bunnelby and Eevee could be really interesting. It might be about their adventures in the Pokémon world. Maybe they team up to find a rare item or to rescue a captured Pokémon. They could explore new regions together, facing different types of Pokémon and trainers along the way.