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.
A possible plotline could be that Bardock, in the afterlife, is able to communicate with Goku in his dreams. He warns Goku about an upcoming threat that is even more powerful than the villains he has faced so far. Goku then starts a new training regime in preparation for this threat, and along the way, he discovers more about his father's past and the true potential of the Saiyan race.
One great Bardock in Dragon Ball Z fanfiction is often depicted as a fearless and noble Saiyan. He is shown as a warrior who, despite the cruel nature of the Saiyan race at that time, had a sense of honor. In some fanfictions, he manages to break free from the control of Frieza in more creative ways than in the original story, making his character even more complex and interesting.
Well, it could be that Goku meets Bardock in a dream - like state. Bardock appears to Goku to pass on some long - lost Saiyan knowledge or a special technique. Goku, being eager to learn more about his heritage, listens intently. As they interact, Goku might feel a deep connection to his father that he never felt before. This could also lead to Goku having a new understanding of his Saiyan nature and using it to become even stronger in his future battles.
A popular version of Bardock in fanfiction is the one who has a premonition of the destruction of the Saiyans much earlier. This Bardock then tries to take actions to prevent it, like gathering other Saiyans who might be sympathetic to his cause. It makes him a hero figure right from the start, rather than just a victim of Frieza's wrath as in the original story.
In this fanfiction scenario, it could be an extremely emotional encounter. Goku, who has grown so much in Dragon Ball Super, finally meeting his father Bardock. Maybe Bardock gets to see how his son has not only become a powerful Saiyan but also a protector of Earth. It could lead to some interesting exchanges about Saiyan heritage and the future of the Saiyan race.
One possible scenario could be an emotional reunion. Bardock, having seen Goku's future through his premonition ability, might be filled with pride. He could see how Goku has grown and the hero he has become in protecting the Earth. Another scenario could be Bardock arriving at a crucial moment during a battle Goku is in and lending his Saiyan strength to help Goku out. This would not only show their Saiyan connection but also the power of family unity in the Dragon Ball Z universe.
Goku and Bardock's relationship might start off rocky. Bardock might be disappointed that Goku doesn't have the typical Saiyan aggression. But as they communicate, Goku shows Bardock the power of friendship and protecting the weak. Bardock starts to respect Goku's way. And Goku, in turn, starts to embrace his Saiyan heritage more because of Bardock. They could end up being a great team, with Bardock guiding Goku in understanding his Saiyan powers better.
Bardock is a tough and battle - hardened Saiyan. When he meets Goku, who has a more pure - hearted and friendly personality, there could be an interesting contrast. Bardock might be initially skeptical of Goku's 'soft' ways but then come to respect his strength which comes from his good heart. Goku, on the other hand, would be curious about his father and would try to show Bardock the value of protecting others, not just for the sake of battle like the Saiyans usually do.
One interesting 'Dragon Ball Z Bardock' fanfiction could be about Bardock surviving and coming back to change the course of Saiyan history. It might explore his relationships with other Saiyans in a new light, like how he'd interact with Goku differently.