In this fanfiction plot, a powerful sorcerer or some sort of interdimensional being could be the cause of the fusion. The fused Naruto - Goku would have an insane amount of power. They could travel at super - fast speeds like Goku and also use shadow clones like Naruto. Their power level would be off the charts. They might end up in different parts of the new world they're in, trying to find each other and figure out what happened, all while being chased by enemies who want to study or destroy their new form.
In fanfiction, if Goku Black fused with Goku, it could potentially create an extremely powerful being. This new entity might have a mix of Goku's pure heart and Goku Black's more sinister motives, which could lead to a complex internal struggle. Their combined power could be off the charts, perhaps strong enough to defeat any foe in the Dragon Ball universe. However, it could also cause chaos as their different personalities clash within the fused form.
Maybe it would be a combined form of some of Naruto and Goku's most powerful enemies. For example, if Frieza and Orochimaru somehow combined their powers and knowledge. They would be a very tricky opponent for the fused Naruto - Goku as they would know the strengths and weaknesses of both heroes.
The plot could involve Goku and Goku Black fusing accidentally. Maybe due to some strange energy anomaly. And then they have to figure out how to control this new form. They might initially be feared by their friends because of Goku Black's reputation, but then they prove that they are on the side of good by using their new powers to protect the Earth from an impending threat that no one else could handle.
Their fused form might have Goku's spiky hair, but with some of Goku Black's purple - tinted highlights. The body would be muscular like Goku's, but with a more menacing stance similar to Goku Black. The clothing could be a combination of Goku's orange gi and Goku Black's black under - shirt, maybe with some red accents added in for an extra pop of color.
One possible plot could be that Naruto somehow ends up in the Dragon Ball universe and through some strange turn of events, becomes Goku's father. He could teach Goku his ninja skills in addition to his martial arts training. Naruto's strong sense of justice and never - give - up attitude would influence Goku a great deal, leading to a more complex and interesting character for Goku.
It could lead to them becoming an almost invincible force, easily defeating most enemies.
In such a fanfiction fusion, Naruto might gain some of Bardock's battle instincts. Bardock was a fierce Saiyan warrior, so Naruto could potentially have an even greater edge in combat. He might also inherit some of Bardock's Saiyan traits, like enhanced strength and speed at a more fundamental level. This could make him even more formidable against powerful foes in the Naruto universe.
Well, it could be really cool. Naruto's ninja skills combined with Vegeta's Saiyan power would make for an extremely powerful being. Maybe they'd have Naruto's ability to create multiple clones and Vegeta's energy blasts at the same time. They could also inherit Naruto's determination and Vegeta's pride, which would make for a very interesting personality mix.
Well, Naruto might gain some really strange abilities. Cell can regenerate and absorb energy. So Naruto could potentially have super - enhanced healing powers. He might also be able to absorb chakra from others like Cell absorbs energy. This could make him extremely powerful in battles, being able to quickly recover from injuries and constantly boost his power.
If Naruto fused with Ichigo in fanfiction, it would be amazing. Firstly, their physical abilities would combine. Naruto's enhanced strength and speed from his training, along with Ichigo's superhuman Soul Reaper physique, would make the fused form extremely formidable in battle. Also, their energy sources could merge. Naruto's chakra and Ichigo's reiatsu might form a new type of power that could be used in different ways. It could also lead to a very interesting story arc, with the fused character having to deal with the memories and emotions of both Naruto and Ichigo.