One possible plot could be Ruby being betrayed by her closest friends. Maybe she discovers a dark secret about the Huntsman academies that makes her question everything she has ever believed in. This disillusionment could start her on the path to evil as she feels that the system she has dedicated her life to is corrupt.
The main antagonist could also be a new character created specifically for the fanfic. This character could be an ancient evil that has been waiting for an opportunity to corrupt a powerful Huntress like Ruby. They would then use Ruby's newfound evil nature to further their own dark plans, and Weiss, Blake, and Yang would have to face both Ruby and this new threat.
Well, one possibility is that Ruby could be influenced by a powerful and evil relic. Maybe she discovers a dark side of the relic's power and becomes corrupted by it, gradually turning evil as she starts to value power over her friends and the greater good.
If Ruby turns evil, she could become her own antagonist in a way. Her former self, the Ruby that was good, could be seen as what she is now fighting against. Her friends would also become antagonists as they try to stop her from causing more harm.
If Ruby becomes a Grimm in RWBY fanfiction, it could lead to a really interesting plot. Maybe she could be a special type of Grimm that retains some of her memories and skills. This could make her a very unique and powerful entity. Her transformation might also force the other characters to re - evaluate their views on Grimm. Are all Grimm truly just mindless monsters? Ruby's case could prove otherwise.
One possible fanfic could explore Ruby's journey into womanhood through her leadership experiences in RWBY. As she grows, she might face new challenges that are related to being a young woman in a world full of danger and responsibility. For example, she could struggle with how others perceive her as a female leader, compared to her male counterparts. This could add an interesting layer to her character development.
One idea could be Ruby discovers a new form of nanotech in a hidden part of Remnant. This nanotech could enhance her Crescent Rose, giving it new abilities like shape - shifting or self - repair.
It's not appropriate at all. Fanfiction should be a form of creative expression that adheres to ethical and moral standards. RWBY has a large fan base that includes people of different ages and backgrounds. Creating or promoting fanfics with inappropriate content like this can be offensive and goes against the spirit of the original work which aims to tell exciting stories about heroism, friendship, and self - discovery.
If Ruby turns into a Grimm in RWBY fanfiction, it could be a really dark turn. Her silver eyes, which are usually a weapon against Grimm, might change. She might start to be attracted to the Grimm way of life. But on the other hand, her friends would never give up on her. They would try to find a way to reverse the transformation. Maybe they would search for some ancient magic or technology. It would be a story full of conflict, both internal for Ruby and external between her friends and the Grimm world.
Well, it could involve Ruby being influenced by an evil force in this fanfic. Maybe she's taught dark magic or has her moral compass twisted. For example, she might start seeing the world in a more cynical way and use her powers for less noble purposes.