If Ruby has a new identity, Weiss might initially be suspicious. Since they have a complex relationship, Weiss could think Ruby is up to something. But as the story unfolds, Weiss might see the good in Ruby's new identity and their bond could strengthen in a different way.
For Yang, it could be a shock at first. Yang is used to Ruby as she is. But Yang's love for her sister would likely make her try to understand and support Ruby's new identity. However, there might be some friction as Yang tries to figure out how much of 'Ruby' is still there, which could lead to some emotional and heart - to - heart conversations between them.
It could strain her relationships. Her friends might be a bit scared or confused by her new form. They may not know how to interact with this 'Red' Ruby at first. For example, Weiss might be more hesitant to trust her, thinking that this change could make Ruby unstable.
On the other hand, it could cause some strain. If Ruby's magic is unpredictable, it might accidentally put her team in danger. This could lead to some arguments and tense moments as they try to figure out how to deal with this new aspect of Ruby. But through communication and training, they would eventually learn to work with her magic and grow even stronger as a team.
Ruby's sleepwalking might also lead to some misunderstandings. If she sleepwalks into Weiss's personal space, Weiss might initially think Ruby is being rude or inconsiderate. But once they figure out it's because of her sleepwalking, it could lead to a deeper understanding between them. Weiss might become more empathetic towards Ruby's involuntary actions, and they could become closer friends.
If Coco is injured, her teammates might become overly protective. For instance, Velvet could be constantly by her side, making sure she doesn't overexert herself. This could initially be a bit annoying for Coco but she would come to appreciate it as a sign of friendship.
One idea could be that Ruby has to assume a new identity to infiltrate a secret organization within the RWBY universe. Maybe she has to hide her silver - eyed powers and act as a normal Huntress in training. This would lead to her having to rely more on her basic combat skills and wits, creating some tense and exciting fight scenes.
It can make her relationships strained. Ruby might push her friends away because she's afraid of hurting them or burdening them with her problems. For instance, she could be short - tempered or distant, causing her friends to be confused and concerned.
With Weiss, their relationship could be more strained at first. Since Weiss has some preconceived notions about Faunus, she might be initially distrustful of Ruby. But as time goes on, they could overcome this. With Blake, they might bond more deeply as they both share the Faunus experience in a way. And with Yang, Yang would be very protective of Ruby, especially if Ruby faced any discrimination because of being a Faunus.
When Ruby becomes a demon in this fanfiction, her relationships with her team are bound to change drastically. Her new form and the powers that come with it could make her more unpredictable. Her team members like Pyrrha (if she was still around) might see her as a danger to the team. This transformation could lead to a lot of mistrust and conflict within the group as they struggle to come to terms with Ruby's new state.
Blake could share her own experiences of dealing with difficult emotions. Since Blake has a complex past, she can empathize with Ruby on a deeper level. She might hold Ruby's hand and tell her that it's okay to feel sad. Jaune could be a bit clumsy in his attempt but his sincerity would shine through. He might crack a few jokes at first to lighten the mood and then offer some words of encouragement.
Her secret identity as a street racer could put a strain on her relationship with Edward. He might be worried about her safety and not understand why she would engage in such a dangerous activity. On the other hand, it could make Jacob more interested in her, as he might admire her courage.