It could be a story of redemption for Raditz. He starts off as a bit of a villain, but through interactions with Bardock (either as a memory or some kind of spirit guidance) and Goku's influence, he changes his ways. They could all be training together on Planet Vegeta before its destruction, with Bardock teaching them valuable Saiyan combat techniques and life lessons that shape them into the characters we know.
In the 'Bardock Saves Raditz' fanfic, perhaps Bardock discovers a way to time - travel. He goes back to the moment when Raditz is about to die. Bardock could use his own power to shield Raditz from Goku's Kamehameha. Then, they team up and start exploring other planets, trying to find a new place for the Saiyans to thrive, away from Frieza's tyranny.
Bardock's power could be shown as more raw and instinctive. Since he was a pure - blooded Saiyan from a time when Saiyans were more about brute force and conquering. Raditz might have a power level that is in between Bardock and Goku. His power could be more focused on intimidation at first, but as the fanfic progresses, he could develop it further. Goku's power, on the other hand, would be more about growth and adaptability. He learns from his battles and constantly improves, so his power could be shown as evolving more rapidly than the others.
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.
One idea could be to focus on Bardock's perspective before his fateful battle. Maybe explore his thoughts about his son Goku being sent to Earth and his own impending doom. He could have some premonitions about Goku's future role in saving the universe.
In a 'Bardock meets Goku' fanfic, the plot might involve Bardock being brought back to life by the Dragon Balls. He then sets out to find Goku. When they meet, Goku is initially confused but then realizes it's his father. They could then train together and Bardock could teach Goku some long - lost Saiyan techniques. It could also be a more emotional meeting where they talk about Goku's past and his mother.
Definitely include Bardock's last stand. His heroic yet doomed battle is a crucial part of the Saiyan lore. It could be written in great detail, with Bardock using his full power against Frieza's forces.
One possible plot could be that Goku, having achieved new levels of power, somehow travels back in time to meet Bardock. Bardock, initially shocked, quickly realizes this is his son. They could have a sparring session where Bardock sees the full extent of Goku's power and is proud. Then they might sit and talk about Goku's life on Earth, and Bardock could share some of his own past battles and the reasons he sent Goku away.
Perhaps the main antagonist could be a new character. This new character could be an ancient evil that has been awakened by the presence of the Saiyans on Earth. They see Bardock and Raditz as a threat to their plans of taking over the universe and thus try to eliminate them.
Well, it could be about a lot of things. Maybe it's a fan - created story where Chilled, Bardock, and Goku are all involved in some sort of adventure or conflict. It might explore their relationships, like perhaps a scenario where Goku has to face off against Chilled while Bardock's legacy or influence somehow plays a part.
In a 'Bardock meets Goku fanfiction', perhaps Bardock is pulled through time and space and lands on Earth during one of Goku's battles. Goku is shocked to see his father but quickly accepts him. Together, they team up against a powerful villain. Bardock shares his Saiyan knowledge with Goku, which helps Goku unlock new powers and defeat the enemy.