Perhaps the 'rose' in the title has some hidden power, and the betrayal is actually an attempt to protect this power from falling into the wrong hands. It could also be that the betrayer has been mind - controlled, and once the control is broken, they have to regain the trust of their friends.
One possible plot twist could be that the character who seems to be the betrayer is actually being framed. Another might be that the betrayal is part of a bigger plan to save the RWBY world from an even greater threat.
Well, 'Betrayal of the Rose' in RWBY fanfic might explore themes of trust and deception. It could be about a character who betrays the group, perhaps for power or personal gain. Maybe it delves into the emotional turmoil of the other characters as they deal with this betrayal.
Well, they might be shocked. In the RWBY universe, the concept of betrayal is quite serious. If it's a Rose character being betrayed, the team could first show disbelief. They trust their comrades deeply, so this would be a huge blow to their morale.
Perhaps a plot twist would be that during the fight, Tai discovers a secret about Raven that completely changes his perception of her. For example, he finds out that she has been working undercover to stop a greater threat all along, and their fight then turns into a reluctant alliance against a common enemy.
One possible plot twist could be that RWBY initially believes Salem's motives are good. Since she raised them, they might be blind to her true evil nature at first. For example, Salem could have presented herself as a protector against some other greater threat, making RWBY question their newfound allies when they start to oppose Salem.
One possible plot twist could be that the characters raised by Grimm end up being the ones to save the RWBY world. Despite their upbringing, they develop a sense of justice that is different from the norm. Another could be that they have a hidden power that is related to their Grimm - raising, which gives them an edge over the regular Grimm.
One possible plot twist could be that Adam has a hidden weakness that Sun discovers during the fight. Maybe it's related to his past or his weapon. Another could be that Sun is actually being controlled by an outside force and Adam has to decide whether to take advantage of it or help him.
It could be an enemy in disguise. Maybe a Grimm has managed to infiltrate their ranks in a clever way and then betrays the Rose character. Grimm are known for their devious ways and this would be a very RWBY - like scenario.
One possible plot twist could be that Ruby's transformation into 'Red' gives her new and unexpected powers. Maybe she can now manipulate fire in a way she couldn't before. This would change the dynamics of her battles and how she interacts with her team. Another could be that this new form comes with a different personality. She might be more aggressive or confident, which could lead to some clashes with her friends who are used to the old Ruby.
There could be. Maybe in the fanfic, while watching Volume 4, a character discovers a hidden detail that changes the way they view an entire event. For example, they might find out that a certain character was being manipulated more than they thought.
Maybe the seventh swordsman has a secret power that is unleashed when Naruto is in a dire situation. This power could be something that was thought to be lost or forgotten in the Naruto world, and its appearance changes the entire dynamic of the story.