Who might be the main characters in 'a grimm fantasy rwby fanfic'?

Well, aside from the main RWBY team, it could also have other characters from the RWBY universe as the main focus. For instance, Professor Ozpin might play a major role in a 'a grimm fantasy rwby fanfic'. He has a lot of knowledge about the world and the Grimm, so he could be leading the fight against the Grimm in a more fantastical scenario. Or perhaps Qrow, with his skills and connection to the story, could be a central character. And don't forget about the villains like Cinder Fall. In a fanfic that focuses on the Grimm, she could be teaming up with the Grimm in some new and dangerous way, making her a main character in the story.

In a 'a grimm fantasy rwby fanfic', the main characters could also be some new original characters created by the fanfic writer. These new characters could be a group of hunters or huntresses who have a special connection to the Grimm. Maybe they have a unique ability to communicate with the Grimm or they are descendants of an ancient group that has been fighting the Grimm for centuries. They could team up with the RWBY characters or they could be on their own adventure, with the Grimm as their main adversary.