One possible plot for this fanfiction could be that Bardock's return is not a simple one. He might be brought back by some sort of time - travel or resurrection magic. His return could stir up old rivalries among the Saiyans. And as he tries to fit into the current Dragon Ball Z universe, he discovers a conspiracy that threatens not only the Saiyans but the entire universe. So, he has to fight against this conspiracy while also trying to reconnect with his son Goku in a more meaningful way.
Obviously, Bardock himself. And of course, Goku would likely be in it since he's Bardock's son. Vegeta might also show up, as he is an important Saiyan character. There could also be other Saiyans like Nappa or Raditz, especially if the story is about Bardock trying to reform or reunite the Saiyan race.
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.
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 vary a lot. In some fanfics, Bardock might be reborn with new powers or a different destiny. Maybe he gets to change the future of the Saiyan race. But it really depends on the author's creativity.
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 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.
One idea could be exploring their relationship before Bardock was sent on his final mission. Maybe a story about them training together and sharing their dreams for 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.
The plot might involve a new threat emerging on the beach. For example, an alien who is attracted to the energy of the Z - fighters shows up. The fighters then have to protect the beachgoers while also trying not to cause too much destruction. Piccolo could use his powers to create a shield around the beach area to protect everyone.
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.