Well, they might be really shocked at the power levels of Goku and Broly. RWBY characters are used to their own kind of battles, and seeing the insane energy blasts and transformations in the Goku vs Broly fanfic could leave them in awe. They might start thinking about how they could incorporate some of those powerful moves into their own fighting styles.
In a Goku vs Broly crossover fanfiction, anime characters could have different reactions. Some might see Goku as a symbol of justice and be inspired by his never - give - up attitude. On the other hand, Broly's raw power could intimidate those who value brute strength. And there could also be characters who try to interfere in the fight for their own motives, like to stop the destruction that such a powerful battle could cause.
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.
If anime characters are in awe, they might stay out of the fight and just be observers, which could keep the focus mainly on Goku and Broly. So the plot would be a more straightforward battle between the two.
Vegeta could also be an interesting choice. Vegeta has his own pride and issues with power, much like Broly. In a crossover fanfiction, they could start off as rivals, constantly trying to outdo each other in terms of strength. But as the story progresses, they might find common ground and have to work together against a common enemy. This would be a great way to explore both of their characters in more depth.
One common theme is power and its control. Since Broly is known for her extreme power in the original series, in the fanfictions with a female Broly, a lot of stories focus on how she manages this power, especially in a world dominated by male Saiyans. Another theme is identity. As a female in a male - centric universe, she often has to find her place and prove herself.
In a Broly - losing - control scenario in a DBZ reader insert fanfic, the story might focus on how the reader's actions affect the outcome. For example, if the reader is a Saiyan as well, they could try to communicate with Broly on a level that other characters can't. They might understand his pain of being an outcast and use that connection to stop his rampage. It could also be that the reader has some knowledge from the future or another dimension that gives them an edge in dealing with Broly.
One popular 'dbz broly x trunks fanfic' is 'The Unlikely Bond'. It explores an interesting dynamic between them as they face a new threat together in a creative storyline.
Another theme is redemption. Given her potentially villainous nature in the original, many fanfics give her a path to redemption. This could involve her making amends with characters she has wronged in the past. It often involves her learning about friendship and loyalty along the way. For instance, she might start off as a loner but gradually form bonds with other Z - fighters.