Some fanfictions might have a plot where Goku and Naruto are in a training - like fight. They exchange techniques and learn from each other. For example, Goku could teach Naruto about ki control, and Naruto could show Goku how to use chakra in a more strategic way. Their fight could be less about winning and more about mutual growth and respect for each other's abilities.
Perhaps the reincarnated character has to face a situation where they are not fully accepted as Goku by his friends and family. They then have to prove themselves not just in terms of strength but also in terms of character, and in the process, they form new and deeper relationships with the Z - fighters.
In a straight - up power comparison, Goku has the ability to reach extremely high power levels that can destroy planets. But Naruto has the power of the Nine - Tailed Fox and his Sage of Six Paths mode which also gives him immense power. If the fight takes place in Naruto's world, Naruto could use the environment to his advantage, like summoning giant toads or using the terrain. On the other hand, if it's in a more open space like in Goku's battles, Goku could use his flight and long - range attacks more effectively. So it's hard to say who would win definitively.
One possible storyline could be that Naruto is somehow transported to Goku Black's universe. There, he has to face Goku Black who sees him as an intruder. Naruto would have to quickly learn about Goku Black's powers and find a way to fight back using his ninja skills. Another storyline could be that a powerful villain creates a rift between their two universes and pits them against each other. They start off as enemies but then realize they are being manipulated and team up to fight the real villain.
In Gohan vs Naruto fanfics, a really cool plot is when their powers get combined somehow. For example, due to a magical or scientific accident, Gohan's ki and Naruto's chakra merge, creating a new and powerful force. Another interesting plot is when they have to fight in a world that has rules that are different from both of their own. This forces them to adapt in unique ways. Also, a plot where they are both de - powered and have to rely on their wits and basic fighting skills to compete can be very engaging.
In some 'oc son of goku fanfiction', a common plot is the OC's struggle with his identity. He is the son of Goku, a great hero, but he wants to make a name for himself. So he might embark on a quest to find a new form or a new fighting style that is all his own. Also, there could be a plot where he has to deal with the jealousy of other Saiyans who feel he gets special treatment due to his father.
One interesting plot could be Goku having to balance his training and his relationships with the various characters in his harem. For example, he might have to deal with the jealousy among the girls when he spends more time with one over the others.
One interesting plot could be Goku and Fem Frieza having to team up against a new, powerful enemy. Maybe this enemy is threatening both of their planets or has some power that neither can defeat alone. Another plot could be Fem Frieza falling in love with Goku and trying to change her evil ways to be with him, but struggling with her past and her reputation among the villains.
In a fanfiction battle, perhaps the fight begins with Naruto trying to talk to Goku first, to understand his intentions. Goku, not really understanding Naruto's world, just wants to test his strength. So he attacks without warning. Naruto quickly enters his Nine - Tails Chakra Mode to defend himself. The fight then escalates as Goku powers up further. The two exchange blows, with Goku's punches creating shockwaves and Naruto's attacks leaving marks on the ground. As the fight goes on, they both start to respect each other's power and skills, and it becomes more of a battle of wits as well as strength.
One interesting plot could be a competition between them for a powerful magical artifact. Percy uses his water - based powers, Jason his lightning and flight, and Nico his control over the dead to outwit each other in a race to find it.
One interesting plot twist could be that Goku and Beerus end up teaming up instead of fighting. Maybe they discover a common enemy that is even more powerful than them. Another could be that Beerus loses his power temporarily and Goku has to protect him from other villains while also trying to figure out how to return Beerus' power.