It could also be a new character introduced just for the fanfiction. This new character might have some hidden motives that lead to the betrayal of the Rose character, which would then cause all the reactions from the RWBY team.
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.
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.
They might be shocked. In many cases, when a character like Jaune is betrayed in fanfiction, the RWBY characters could initially show disbelief as they've come to know him. It would disrupt their view of the group dynamic.
Well, they might be shocked at first. The characters in RWBY are all about loyalty in their own group, so seeing a 'Betrayed Rose' would be quite a jolt. They could start to question the motives behind the betrayal, whether it was for power, love, or something else entirely.
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.
Cinder Fall could be a likely betrayer. She's already a villain in the original series, and in a fanfiction, she could pretend to be an ally to one of the RWBY members only to betray them at a crucial moment, perhaps leading them into a trap set by Salem.
It can show the depth of their friendships. If Jaune is betrayed, it tests how far the RWBY characters are willing to go for him. For example, if Ruby really considers Jaune a close friend, she'll do whatever she can to support him and get to the bottom of the betrayal.
It could be Luke. Even in a time - travel scenario, Luke's bitterness towards the gods might lead him to betray Percy. He could use time - travel to his advantage, perhaps making deals with past versions of enemies to stop Percy from achieving something that would benefit the gods.
It could be a jealous rival of Twilight. Maybe someone who has always been envious of her status and power in Canterlot.
Another possibility is that it could be a new character introduced in the fanfiction. This new character could be someone who gains Harry's trust quickly but then betrays him for personal gain or because they are secretly working for an enemy. For example, a new student at Hogwarts who seems friendly at first but is actually a spy for a dark wizard.
These different reactions based on their personalities would create a lot of tension and conflict within the fanfiction. It would also show the complexity of their relationships. For instance, Ruby's attempts at reconciliation might clash with Yang's more aggressive approach. Weiss's pride could make it difficult for her to forgive easily, while Blake's empathetic view could be a bridge between the two extremes. This all would make for a very interesting read in the fanfiction.