Maybe Bardock's past and his own struggles in the Dragon Ball universe could parallel Naruto's journey in some way. For example, both are from warrior - like races (Saiyans and the Uzumaki clan which has a reputation for being strong). Their fates could be intertwined as they face challenges together. Bardock could teach Naruto some of his Saiyan fighting techniques, which Naruto could then adapt to his own ninja style.
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 Pan, being from a different time period than Bardock, accidentally travels back in time and meets him. Maybe she initially mistakes him for Goku due to their similar Saiyan features. Bardock could be initially suspicious of her but then realize she has a good heart.
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, it could start with Gohan exploring an ancient Saiyan relic. Unbeknownst to him, this relic has the ability to bring back the spirit of Bardock. Once Bardock appears, he is initially confused about where he is and who Gohan is. Gohan, being the kind - hearted person he is, explains the situation. As time passes, Bardock starts to train Gohan, pushing him to new limits. Gohan also shares his knowledge of Earth's culture and values with Bardock, which makes Bardock see a different side of life compared to the brutal Saiyan culture he knew. This interaction could change both of their perspectives and lead to a new understanding between the past and present of the Saiyan race.
In the 'Gohan meets Bardock' fanfiction, it might start with Gohan stumbling upon an ancient Saiyan relic that somehow connects him to Bardock. Bardock then appears as a spirit or through some time - traveling magic. They have a deep conversation about the purpose of the Saiyan race. Bardock could be proud of Gohan for breaking the mold of the typical Saiyan, being more about protecting the innocent rather than just fighting for power. Gohan, in turn, could be inspired by Bardock's raw Saiyan spirit and find a new way to combine it with his own values.
If other characters from both universes were involved, like Goku from Dragon Ball and Sasuke from Naruto. Goku and Naruto might get along really well because they both have a pure - hearted approach to fighting. Sasuke, however, might be more suspicious of Bardock and the Saiyan way. He might see them as a threat to his own power - seeking goals. Bardock, in turn, might not trust Sasuke's motives right away.
Well, in a Naruto and Thor crossover fanfic, maybe Naruto is on a journey and accidentally stumbles into a portal that leads him to Asgard. There, he meets Thor. Thor is intrigued by Naruto's tenacity and ninja skills. They could exchange their combat techniques. Naruto shows Thor how to move stealthily like a ninja, and Thor teaches Naruto some of his Asgardian battle tactics. And together they could face a threat to Asgard that is related to some dark chakra - like magic that has seeped into Asgard from another dimension.
One possible plot could be that Naruto goes on a mission to the Hidden Cloud Village where he meets Samui. They are initially at odds due to the historical tensions between their villages. But as they face a common enemy, like a rogue ninja group trying to steal a powerful jutsu from both villages, they start to work together. Naruto's determination and positive attitude gradually influence Samui, and they form an unlikely friendship that might even lead to a deeper understanding between the Leaf and Cloud villages.
Perhaps it could be a story of redemption for Lucifer. Naruto, with his unwavering belief in the good of people, sees something in Lucifer that could be saved. He tries to convince Lucifer to turn away from his more evil tendencies. Along the way, Naruto has to face challenges in Lucifer's world, and Lucifer has to face his inner demons as Naruto encourages him to change.
One possible plot could be that Tony Stark, while testing some new interdimensional tech, accidentally ends up in the Naruto universe. He could use his advanced technology to help the ninja in various ways, like creating new weapons or defenses against the Akatsuki. Maybe he teams up with Naruto and they combine their powers to defeat a common enemy, such as a new super - powerful villain that neither world could handle alone.