If Jaune and Blake were expelled in a fanfic, the emotional impact on the other characters would be significant. Ruby would not only lose a friend but also someone she saw potential in (Jaune). Weiss might struggle with the idea that the school she once thought was so great could expel students so easily. Yang would be worried about Blake and might go after her. This could split the group further. Story - wise, new plotlines could emerge, such as the expelled duo trying to clear their names or finding a new way to fight the Grimm that doesn't involve the academies.
In a fanfic, if Jaune and Blake were expelled, it would completely disrupt the normal flow of the RWBY story. First of all, Jaune has been developing his skills and relationships within Beacon. His expulsion would cut that short and force him to find a new path. Blake, who has her own complex backstory, being expelled could send her back into a world of secrecy and solitude. The story could then focus on their individual struggles outside of Beacon. They might have to face Grimm alone, or deal with other threats that the academies usually protect against. And the relationships they had with the other RWBY characters would be strained, as they are now on the outside looking in.
The story would change a great deal. Their expulsion would mean a loss of two important characters from the main group. This could lead to the remaining characters having to reevaluate their strategies. Without Jaune's growth and potential, the team might lack a certain kind of leadership or support. And without Blake, the team would lose her unique skills and perspective. It could also create a rift between the students and the school, with some blaming the school for being too harsh and others thinking it was a necessary decision.
If Jaune and Blake were expelled in a fanfic, it could lead to a whole new set of adventures. Maybe they would form their own group outside of Beacon. They could encounter new enemies and allies, and their relationships with the remaining RWBY characters would be greatly affected. For example, Ruby might be really sad and try to find a way to bring them back. Yang could be angry at the school for expelling Blake. And Weiss might see it as an opportunity for the school to become more 'elite' but still have some mixed feelings.
In some fanfictions, they might team up to prove their worth and get reinstated. They could go on a journey to uncover a conspiracy that led to their expulsion.
Jaune would likely become more self - reliant. Without the support of his friends and family, he'd have to learn to take care of himself. He might become more cautious in trusting others, having been betrayed by those closest to him.
If Jaune is betrayed, RWBY's relationships with him could become stronger. They might feel more protective of him. Ruby would be more attentive, Weiss might be less cold towards him, Blake could offer more support, and Yang would be like a big sister to him.
It could completely change the dynamic. Their friends would have to deal with their absence, which might lead to some characters going on personal quests to get them back.
His character could become more self - assured. Jedi are known for their confidence in their abilities, and Jaune might gain that as he masters Jedi - like powers.
Ruby would be deeply saddened. She might blame herself for not being able to protect Blake. Weiss would probably be in shock at first, then become more determined to fight against whatever caused Blake's death. Yang would be furious and seek revenge. She has a very close bond with Blake, and her death would likely fuel Yang's anger towards the enemy.
One possible plot could be that they are banished due to a false accusation. For example, they might be wrongly blamed for a crime they didn't commit within the RWBY universe. Maybe some powerful figure wants to get rid of them for political reasons.
It could be Cinder Fall. She's always been a major villain in RWBY. She might be the one who arranges for Blake and Jaune to be banished as part of her evil plan to gain more power or cause chaos in the world of Remnant.
Jaune could also become angry and frustrated. He might feel that the system is unfair and that he's being wrongly punished. So he could lash out at those he believes are responsible for his expulsion, whether it's a fellow student who set him up or a teacher who didn't give him a fair hearing. In some cases, he may even try to expose the wrongdoings or secrets of the school as revenge for his expulsion.