Ruby might develop a darker side to her personality. Being exposed to Cinder's evil deeds and the dark world she inhabits could cause Ruby to have some internal conflict. She might struggle with feelings of anger and resentment towards Cinder and those like her, and this could manifest as a more brooding or sullen aspect of her personality, at least until she figures out how to deal with her new situation.
She could become more calculating. Ruby is usually quite impulsive, but in Cinder's company, she'd have to think several steps ahead. Cinder is always scheming, and Ruby would need to be able to anticipate her moves. This would make her less likely to rush into things and more likely to weigh the consequences of her actions carefully.
Ruby would likely become more cynical. She's used to being in a team of heroes and believing in the good of people. But being around Cinder, who is manipulative and self - serving, would make Ruby question her own ideals. She might start to doubt the purity of her motives and become more guarded.
If in fanfiction Cinder is Ruby, it would be a total game - changer. Ruby is the symbol of hope in RWBY, and Cinder is a symbol of destruction. So, this switch would create a really interesting narrative. The story could explore how Cinder, in Ruby's body or identity, would deal with Ruby's responsibilities. Would she try to uphold Ruby's values? Or would she slowly corrupt them? And how would the other characters react? They might initially trust her because she looks like Ruby, but as they start to notice the differences in her behavior, it would lead to a lot of conflict and drama.
One great RWBY Ruby and Cinder fanfiction is 'The Unlikely Alliance'. It explores a scenario where Ruby and Cinder are forced to work together against a common enemy. The story does a great job of developing their characters in this new context.
One interesting concept could be the exploration of their opposing natures. Ruby is often seen as pure - hearted and full of hope, while Cinder is more devious and power - hungry. In fanfiction, this contrast can lead to some intense character - driven stories where they either learn from each other or clash in more complex ways than in the original series.
The exploration of their backstories together is also a theme. Writers may create scenarios where Ruby and Cinder's pasts are somehow intertwined, perhaps revealing secrets that change their relationship in the RWBY universe.
I'm not sure specifically as there could be many different takes in such a fanfiction. It might involve Ruby growing up under Cinder's influence, which could lead to a complete change in her character, values, and fighting style. Maybe Cinder has some ulterior motives for raising Ruby, like using her as a weapon or a pawn in her grand scheme against Beacon Academy and the other Huntsmen and Huntresses.
Cinder might become more adaptable. In the RWBY world, she is used to a certain set of rules and powers. But in the Halo universe, she has to quickly learn new things. So she could become more open - minded about different ways of fighting and surviving.
In some fanfictions, Cinder's change way might involve a shift in her alliances. For example, she could break away from Salem due to some internal conflict. This could lead to her seeking refuge with the main characters, and in the process, she has to learn new values and ways of life. She may struggle with her past actions but gradually grow into a better, more complex character.
There's also 'Cinder's Redemption Arc with Ruby'. In this fanfiction, Ruby plays a key role in Cinder's journey towards redemption. It delves deep into Cinder's past traumas and how Ruby's kindness makes her question her own actions and motives. This one is really interesting as it gives a lot of depth to Cinder's character.
Obviously, Ruby and Cinder are the main characters. Ruby is known for her optimism and combat skills with her scythe. Cinder, on the other hand, is a more complex and often villainous character with her own set of powers.
Another idea is a time - travel fanfic. Cinder travels back in time and meets a younger Ruby. She could try to manipulate Ruby into following a different path, but Ruby's strong will and sense of justice might resist. This would create a lot of conflict and interesting character dynamics as Cinder tries to change the future and Ruby tries to protect it.