Salem is also a very popular villain in RWBY fanfiction. Given her status as the main overarching villain in the series, fanfic writers like to expand on her backstory, her motives, and her long - term plans. There could be fanfictions that focus on her interactions with other villains in a more detailed way.
Some RWBY villains fanfiction might put the villains in situations where they have to face moral dilemmas. Like, if Tyrian was forced to choose between following Salem blindly or doing something that went against her orders but was morally right. This could lead to a very interesting character development for him.
Well, they might be shocked at the turn of events in Volume 3. For example, Cinder could be secretly pleased with how her plans are progressing while outwardly showing a calm facade. Roman might be frustrated if things don't go as he expected in the fanfiction, like if his heists are thwarted more easily than in the original story.
Villains might find it interesting to see how the RWBY universe is reimagined in fanfiction. They could be amused by alternative storylines or character portrayals that deviate from the original. Maybe they would pick up on new ideas for their own 'evil' plans within the context of the RWBY world.
Some of the RWBY villains might be intrigued by the strategic elements in Red vs Blue fanfiction. In RWBY, they are used to battles with semblances and dust, but in Red vs Blue, the battles rely more on regular weapons and teamwork in a different way. They could analyze these new strategies and perhaps even consider applying some concepts to their own plans in RWBY, if possible.
A power - hungry villain like Cinder Fall might not care much for Red vs Blue fanfiction. She is so focused on her own goals of power and domination in RWBY that she would likely see the fanfiction as a distraction from her important business.
Well, Cinder would probably be a bit annoyed if the fanfic doesn't portray her as powerful as she thinks she is. She has a huge ego and seeing herself as weak or less important in a fan - created story could really irk her. On the other hand, if the fanfic shows her in a really cool and dominant way, she might secretly enjoy it.
It could be the classic villains from the original series like All For One. He might be interested in baby Deku's potential quirk. Another could be Shigaraki, who might see baby Deku as either a threat or an opportunity to disrupt the hero world in a new way.