In some fanfictions, a knight oc could be from a different dimension where the rules of combat and magic are distinct. They come to the RWBY world and their presence disrupts the balance. Their armor might have special properties that are both an advantage and a source of mystery. They might initially be seen as a threat by Ozpin and the others, but as they interact more, they become an important part of the fight against Salem. They could also teach the RWBY characters new combat techniques based on their own knightly training.
Another interesting plot could be Qrow dealing with his own personal demons, like his alcoholism, while still being a father figure. He could struggle to set a good example for his child, but through the story, he gradually overcomes his issues. For example, his child might get into a dangerous situation because of his drinking habits, which serves as a wake - up call for him. And he then starts to change for the better to be a proper father.
One possible storyline could be a redemption arc for Cinder through her relationship with Pyrrha. Maybe in an alternate universe, Cinder realizes the error of her ways and Pyrrha helps her to change. They could start as enemies but gradually come to understand each other.
One possible storyline could be Jaune teaching his child the skills he learned at Beacon. He might pass on his knowledge of combat and strategy, while also instilling in them the values of teamwork and friendship, just as he experienced with his team.
Some fanfictions might have a storyline where the characters swap personalities. Yang could become super shy and reserved, while Blake turns into a hyper - active and overly talkative character. This would lead to all sorts of comical situations as they try to adapt to their new personalities while still facing the challenges of the RWBY world. The team would have to figure out how to work together in this new, wacky dynamic.
One interesting storyline could be a character from RWBY getting injured during a battle and having to recover in the hospital. There, they might meet new allies or face unexpected challenges within the hospital setting. For example, dealing with a shortage of medical supplies due to Grimm attacks on supply routes.
One interesting storyline could be a fanfiction where the characters have to face an ancient evil that was long forgotten in the RWBY universe. This evil could be something that predates the Grimm and has powers that are completely different from what they are used to dealing with.
A third storyline could be Harley Quinn becoming a vigilante of her own kind. Tired of the chaos and destruction caused by the Joker and other villains, she decides to use her skills and knowledge to fight crime in her own way. She might not be as morally upright as Batman, but she has her own code. She could target criminals who are preying on the weak, and in the process, have run - ins with both the police and the traditional superheroes.
One idea could be exploring the backstory of how the Silent Knight came to be. Maybe he was once an ordinary Huntsman who faced a great tragedy that led him to his silent and brooding state.
One interesting plot could be a Knight character who was once on the wrong side, but through interactions with the RWBY team, begins to see the error of their ways and strives for redemption. They might have to face old allies who are still on the dark path and fight against them to prove their new allegiance.
One interesting aspect is how the fanfiction writers blend the world - building of RWBY with their own creative ideas for the OC Hunters. For example, they could create new missions or challenges that these hunters face, which might involve fighting new types of Grimm or dealing with complex political situations within the RWBY world. This can make for a really engaging read as it expands on the already rich RWBY lore.