Ozpin could also be a significant character. He has a long history with Salem and would likely be very concerned about Salem's love for Ruby. His knowledge and influence in the RWBY world could add more depth to the story, as he might try to interfere in this unexpected relationship.
There could also be other characters who play important roles. For instance, Ruby's friends from Team RWBY, like Weiss, Blake, and Yang. They might be suspicious of Salem's intentions towards Ruby and try to protect Ruby from what they see as a threat. Also, Salem's minions could be in the story, and they might oppose Salem's newfound feelings for Ruby.
Perhaps Salem starts to change her ways because of her love for Ruby. She might begin to question her long - held beliefs and actions, which could lead to a lot of drama and conflict within the story. For example, her followers might not understand her new attitude.
The other characters would be shocked. Weiss would probably be the first to try and figure out what's wrong with Ruby. Blake would be worried about Ruby losing her way, and Yang would be furious. Yang might even go on a solo mission to bring Ruby back, not fully trusting the rest of the team to handle it delicately. The rest of the characters like Jaune and Nora would also be in disbelief and would start planning ways to rescue Ruby.
The storyline could be extremely dark. Ruby, being raised by Salem, might be trained to oppose the Huntsmen and Huntresses. She could have a completely different view of the world, seeing the kingdoms as the 'bad guys' and Salem's side as the 'righteous'. Her relationships with her original friends would be in shambles as she would be on the opposing side. For example, her relationship with Weiss would be non - existent as they are on different moral spectra.
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.
One possible plot could be Ruby Rose trying to understand Salem's motives. Maybe Ruby, with her pure heart, believes there's a chance to redeem Salem. She could engage in a series of intense conversations with Salem, where Ruby tries to appeal to any good that might still be in her. This would be a great exploration of the themes of good versus evil and redemption.
One interesting fanfiction could be where Ruby has to face Salem alone in a battle of wits and strength. In this story, Ruby might discover a new power within herself to counter Salem's dark magic.
Well, her sister Yang would definitely be one of the main characters. Yang would be very protective of Ruby and would try to help her in any way she could. Weiss would also be important. She might use her intelligence and Dust - related skills to assist Ruby. And Blake, with her stealth and combat skills, could be crucial in protecting Ruby and guiding her through difficult situations.
There could also be a dynamic where Ruby and Salem are forced to work together for a short time due to some external threat. During this time, Ruby discovers that Salem has some redeeming qualities, like her intelligence and strategic thinking. Salem, on the other hand, realizes that Ruby's optimism and courage are not just naivete. This temporary alliance changes their views of each other and when they part ways, they are no longer the same as they were before.
One idea could be Ruby trying to understand Salem's motives beyond just destruction. Maybe she discovers that Salem has a tragic past that led her to this path and Ruby attempts to find a way to redeem her. Another plot could involve Salem targeting Ruby specifically because of her silver - eyed powers and Ruby having to outwit Salem in a series of battles.
Her Semblance could be more destructive. Instead of using it mainly for mobility and quick attacks, it might be used to cause widespread chaos. For example, instead of just dashing in and out of battles, she could use her speed to create tornado - like effects that cause more damage to her enemies.