It could be an original character created by the fanfic author. This character might be a skilled fighter, maybe with a unique weapon or fighting style, like using a special kind of kunai combined with lightning - based chakra attacks.
Well, in some fanfics like this, the banished mercenary might have unique abilities that set them apart. For example, they could have a special chakra-based power that was feared or misunderstood in the Naruto world. This could lead to them being banished unfairly.
Well, it could be about a Naruto who has god - like powers and gets banished. Maybe he's too powerful for the village to handle, or perhaps there are some political reasons within the village that lead to his banishment. But without reading it, it's hard to say exactly.
Well, without having read it, it could involve Naruto being sent away from his home, perhaps Konoha, and then rising to power in the west. Maybe he has to face new enemies, form new alliances, and deal with the politics and power struggles in that region. It could also explore how his ninja skills are adapted to this new situation and how his relationships with other characters change.
Another theme is adaptation. He has to adapt to the new rules, cultures, and powers of the crossover world. For example, if it's a crossover with a magic - based world, Naruto has to learn how magic works and how to use it. This theme of adaptation makes for some interesting character development.
A 'Naruto get banished yaoi fanfic' is likely about Naruto being exiled from his village and then there are probably yaoi elements involved, which means male - male relationships. It could be about Naruto forming new relationships with other male characters during his exile.
It could be that they are wrongly accused of a crime they didn't commit. Maybe a major incident occurs in the village and they are made scapegoats. So, they are banished as a result of this false blame.
Well, Naruto himself could be a really interesting take on a banished prodigy. Imagine if things had gone differently in the village and he was banished. It would be a huge change from the original story. Shikamaru is also a possibility. He's intelligent and has a lot of potential. If there was some sort of political or power struggle within the village that led to his banishment, it could make for an engaging fanfic. Also, Hinata could be a unique choice. Her shy nature but hidden strength could be explored in a banished prodigy storyline.
Well, one possible plot could be that Naruto, feeling betrayed by the Hidden Leaf, decides to join Akatsuki out of spite. He might start using his powers in a more ruthless way, which could shock his former friends. Akatsuki, on the other hand, would be initially suspicious of him but gradually see his value. They could use him to target the Hidden Leaf more effectively, leading to some intense battles between Naruto and his old comrades.