In a 'Twilight Betrayed by Her Friends' fanfiction, it could be that Twilight's friends become jealous of her powers. They feel overshadowed by her abilities and knowledge. So they start to undermine her at every turn. For example, they might ruin her chances of getting a special magical promotion or getting into an exclusive magical study group. Twilight is heartbroken at first but then decides to prove herself without their support and in the process, she might find new friends who truly appreciate her for who she is.
One possible plot could be that Hermione's friends start believing false rumors about her. For example, they might think she's been stealing potions ingredients for personal gain when in fact she was framed. As a result, they shun her and exclude her from their group activities. This makes Hermione feel isolated and betrayed, and she has to find a way to clear her name and either regain her friends' trust or find new allies.
It could be an outsider who manipulates Twilight's friends. This character might be envious of Twilight's popularity or power in the magical realm. They trick Twilight's friends into believing false things about her, making the friends turn against her.
One possible plot could be that Percy Jackson, in a crossover world, is somehow made to believe that the Twilight characters are a threat to his world. Maybe he's deceived by some dark force into thinking they're planning to take over Camp Half - Blood. So he betrays them by leading an attack on their territory in Forks, not realizing he's been tricked.
In such a fanfiction, perhaps Harry's friends are jealous of his newfound powers or popularity within the wizarding world. So they spread rumors about him being untrustworthy. As a result, Harry is shunned by many in the community. He has to embark on a solo journey to prove his innocence and in the process discovers who his true friends really are.
In a fanfiction where Naruto is betrayed by his friends, it could start with jealousy. Suppose Naruto gets a great power or a special recognition. His friends, feeling overshadowed, might be tricked by an evil force into thinking Naruto is using them. So they betray him, which makes Naruto realize that he has to rely on his own strength and find new allies who truly understand him.
Bell could be deeply hurt by the betrayal. She might start to have nightmares about it. As the story progresses, she could find the strength within herself to confront her so - called friends. She could demand an explanation and then decide whether to forgive them or cut them out of her life completely. She might also become more cautious in making new friends in the future, always being on guard against potential betrayal.
One possible way this could develop is through a misunderstanding. Maybe Naruto is framed for a crime he didn't commit, and his friends believe the false evidence against him. For example, an enemy could plant evidence that makes it seem like Naruto is working with the villains. His friends, not knowing the truth, turn their backs on him. This would lead to Naruto feeling extremely hurt and isolated, and he might have to go on a journey to prove his innocence on his own.
One possible reason could be jealousy. Maybe her friends are envious of Hermione's intelligence and magical abilities. In a fanfiction, this could lead them to betray her to gain an advantage or to make themselves look better. Another reason might be a misunderstanding. A miscommunication or false assumption could cause her friends to turn against her.
It could be that an external force, like a dark wizard in disguise, is the main antagonist. This dark wizard targets Hermione because of her potential to be a great threat to their evil plans. They use magic to cloud the minds of her friends, making them believe Hermione is up to no good. The friends, being under this spell, betray Hermione without realizing they are being manipulated. The dark wizard then watches as Hermione struggles with this betrayal, all part of their grand scheme.
Well, it could be that Twilight discovers some sort of dark secret about the Mane 6 and decides to betray them for what she believes is the greater good. Maybe she's been influenced by some external force.