Well, it would be an extremely powerful combination. Naruto has his ninja skills and chakra, while Broly is a Saiyan with insane strength. Maybe they'd create new and unique fighting techniques. Their fused form could have Naruto's determination combined with Broly's raw power, making them a force to be reckoned with in the fanfiction universe.
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.
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.
Goku could escape by overpowering Broly. He might tap into his Super Saiyan forms, like going into Super Saiyan Blue or even Ultra Instinct if he's pushed far enough. His sheer power and fighting skills could allow him to break free from whatever restraints Broly has put on him.
The story could start with some sort of magical or scientific accident that causes the fusion. Then, they might have to deal with people being afraid of their new, extremely powerful form. Their friends would be confused at first but then try to help them control this new power.
It could be Zamasu. Since Goku Black was Zamasu in Goku's body in the original story, perhaps a more powerful and enraged Zamasu could be the main antagonist. He might be jealous of the new fused form's power and seek to destroy it.
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.
Sure. Fanfiction writers have a lot of creative freedom when it comes to Goku and Female Broly. In some fanfictions, they might be in a romantic relationship, which is an interesting take considering their Saiyan heritage and the way they both value strength. However, not all fanfictions take this route. Some might explore a more platonic friendship where they respect each other's power and learn from one another. You can usually find a variety of these stories by using the search function on major fanfiction platforms.
Yes, in the vast world of fanfiction, there are all kinds of creative and out - of - the - box stories. Some fans like to explore unusual relationships and scenarios, so it's possible that there is such a fanfiction out there. However, it goes against the original canon of the Dragon Ball series in many ways.