In a fanfiction like this, perhaps Bardock is on a mission in the afterlife and it leads him to cross paths with Goku and Chi - Chi. Bardock could test Chi - Chi's strength and worthiness to be with his son. Chi - Chi would rise to the challenge, showing her determination. Goku would be in the middle, trying to make sure his father respects his wife. And in the end, Bardock could give his blessing to their relationship, seeing how happy they are together and how Chi - Chi has made Goku a better person in many ways.
They might start with a big hug. Goku would be excited to meet his father. Then they would start chatting about all kinds of things, like Goku's adventures on Earth.
At first, it might be tense. Bardock is a hardened Saiyan warrior from a different era, and Goku has grown up on Earth with a very different set of values. But as they start to communicate, they would find common ground in their Saiyan blood. Goku's pure - heartedness could gradually win over Bardock, and Bardock's strength and pride could earn Goku's respect.
At first, it could be a bit rocky. Bardock is used to the harsh Saiyan ways, while Goku has been raised on Earth with different values. But as they spend time together, they start to understand and respect each other. Bardock could become a mentor to Goku, teaching him advanced Saiyan fighting techniques and Goku could teach Bardock about friendship and love.
One possible interaction is that Bardock could spar with Goku and Gohan. He'd test their limits and see how much they've learned about fighting. Another could be Bardock sharing stories of Planet Vegeta with them, which would be really interesting for Goku and Gohan to hear.
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.
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.
One possible plot could be that Goku, through some time - travel or interdimensional rift, meets Bardock in the past. Bardock could initially be suspicious of Goku, not knowing he's his son. But as they interact, Goku might show some of his Saiyan power and spirit that reminds Bardock of his own. They could then team up against a common enemy, like a powerful alien race threatening Planet Vegeta.
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.