One plot idea could be that Bardock, in some way, gets to see the future Goku achieves. Maybe through a time - warp or a prophetic vision. Another could be a story where Baby Goku is sent on a special mission, and Bardock's spirit somehow guides him. For example, when facing a really tough enemy, Baby Goku hears Bardock's voice in his head giving him advice on how to fight.
Well, you could have a plot where an enemy from Bardock's past resurfaces and targets Baby Goku to get revenge on Bardock. So Bardock's friends or comrades who might have also survived, come together to protect Baby Goku. This could lead to a whole series of adventures where they train Baby Goku to be strong enough to face this threat and also uncover secrets about their Saiyan race along the way.
A great plot idea is a what - if scenario. What if Bardock didn't die and was able to be part of Baby Goku's early life on Earth? He could teach Goku about their Saiyan heritage much earlier. Or perhaps a fanfiction where Bardock is reborn and has to find and protect Baby Goku from the looming threats that Goku doesn't even know about yet as a baby.
One plot idea could be that Baby takes over Goku's body and tries to use his power to conquer the universe in a more subtle way. He might pretend to be Goku at first and manipulate his friends into doing his bidding without realizing it.
One idea could be that Baby Goku discovers a hidden power within himself while on an adventure with Gine. Maybe they encounter a new and strange enemy that forces Gine to teach Goku some unique skills passed down in their family.
Well, a great plot could be that in his baby state, Goku attracts the attention of an old enemy who wants to take advantage of his weakened state. His friends then have to protect him at all costs. Also, there could be a plot where baby Goku discovers new powers that are unique to his baby form, like the ability to communicate with animals in a special way.
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.
Another plot could involve Bardock having to adapt to the magic - based society of Fairy Tail. He might initially struggle with understanding how magic works, but then discovers a way to combine his Saiyan power with the magic there. For example, he could learn to use ki - based attacks in harmony with Fairy Tail's elemental magics. This would create a unique fighting style that surprises both his allies and enemies.
Some fanfictions explore Bardock's connection to the Super Saiyan legend in more depth. Maybe he had a premonition or some sort of hidden knowledge about it that he was trying to pass on. This can lead to really complex and engaging storylines that add new layers to the Dragon Ball lore.
One idea could be that Goku and Goku Black are forced to team up against an even greater threat from another universe. They start to understand each other's fighting styles during the battle and gradually develop a grudging respect for one another.
In some versions, the female Goku could be part of a prophecy. The two Gokus meet, and at first, there is some confusion and misunderstanding. But as they get to know each other, they discover that they are key to fulfilling the prophecy. They combine their powers and defeat an ancient evil that was threatening both of their worlds.
One idea could be a story where Bulma creates a new device that accidentally sends Goku and her to a parallel universe. There, they have to work together to find a way back home while facing new and strange enemies. Another could be a time - travel plot where they go back in time to before Goku met Chi - Chi and Bulma realizes she has feelings for him. The third idea is a story where Goku and Bulma get trapped on a deserted planet and must rely on each other's skills to survive and escape.