If Ruby joins Roman in the fanfiction, it might start with Ruby being tricked by Roman. He could pretend to have some information that Ruby desperately needs, like the location of a powerful relic that is about to be used for evil. Once she's with him, she realizes that his ways are completely different from hers. However, she decides to stay for a while to gather more intel. During this time, she has to constantly resist his attempts to make her more like him in terms of being less rule - bound.
Well, one possibility could be that Roman joins Beacon under false pretenses. Maybe he's trying to steal some valuable Dust or intel from the school. He could pretend to be a reformed criminal, fooling some of the students and teachers at first. But as the story progresses, his true motives start to surface and the characters have to deal with the betrayal.
If Ruby joins Roman, her character could develop in a more rebellious way. She's always been a bit of a rule - follower in the context of the Huntress code. But being with Roman would expose her to a different set of rules, or rather the lack of them. This could lead her to break some of the traditional Huntress norms. However, she would also be constantly fighting against Roman's more amoral tendencies, which would in turn strengthen her own moral compass in some ways. For example, she might have to stand up to Roman when he wants to do something really bad, like harm an innocent bystander for his own gain.
If Ruby joins Salem in the fanfiction, it could be a very dark turn for Ruby. Salem might manipulate Ruby into believing that her methods are the only way to bring about a new order. However, Ruby's friends would never give up on her. They would try to rescue her, and in the process, Ruby might have a change of heart and turn against Salem, leading to an epic showdown.
It could be that Ruby has to deal with the consequences of a major decision she made in the past. This causes her to question her leadership skills and she embarks on a journey of self - discovery to become a better leader for her team.
The plot could involve Ruby finding a balloon that has strange powers. For instance, it might allow her to fly, which is something she doesn't normally do without her scythe's recoil. This new ability could change the way she approaches battles and exploration in the RWBY world.
I also like 'Ruby and Roman: Unlikely Allies'. This fanfiction shows how Ruby and Roman could team up against a common enemy. The action scenes are well - written, and the dialogue between the two characters is very engaging, showing a different side of their relationship.
Well, one possibility could be that Ruby gains a whole new level of guidance. Ozpin might introduce her to secrets of the world she never knew. Maybe he trains her in unique ways, using his vast knowledge and experience, which helps Ruby become an even more powerful huntress in the long run.
One possible plot could be that Ruby discovers Yamato in a strange new world or dimension within the RWBY universe. She has to figure out how to use it or control it while also facing the challenges that come with it, like other Grimm or villains being attracted to the power of Yamato.
One possible plot could be Ruby initially trying to hide her Grimm part from her friends. As she struggles with newfound abilities and instincts, she has to constantly fight the urge to give in to the Grimm side. Meanwhile, a powerful enemy emerges that she might be uniquely suited to defeat because of her Grimm part, but she has to first come to terms with it herself.
Well, it could be about Ruby struggling to hide her true nature as a Grimm Faunus while still being a Huntress. Maybe she has to deal with the prejudice from others who fear Grimm Faunus.