In some 'harry gets betrayed fanfic', it could be Dumbledore who betrays Harry in a way. Maybe Dumbledore has been using Harry all along for a greater plan without fully disclosing it to him. Harry would feel extremely hurt and betrayed as Dumbledore was like a mentor to him. This would lead to a series of events where Harry questions everything he has known and tries to find his own path.
One possible reason could be jealousy. Maybe the Weaslys in the fanfic become jealous of Harry's fame or special abilities. Another reason might be some kind of dark magic influence on them, which changes their nature and makes them turn against Harry. It could also be due to a misunderstanding. For example, a false rumor spreads about Harry that makes the Weaslys believe he has done something terrible.
Harry might be initially shocked and heartbroken. He trusted the Weaslys like family, so the betrayal would hit him hard. He could become more withdrawn and distrustful of others.
A really engaging 'betrayed Harry fanfiction' is 'The Betrayal Chronicles'. It details how Harry is gradually pushed out of the wizarding community due to false accusations from his so - called friends. The story delves deep into his emotional turmoil. 'When Trust is Broken' is another one where Harry's trust in his friends is shattered, and he has to navigate a world full of enemies while trying to figure out who he can still rely on.
Often, the betrayal is sudden. For example, if it's his friends who betray him, it might start with a small incident that Harry doesn't think much of at first. But then it snowballs into a full - blown situation where his friends turn their backs on him completely. Then Harry has to struggle to deal with this new situation while also facing other threats in the wizarding world.
One popular 'betrayed fanfic' could be in the Harry Potter fandom. For example, some stories where Ron betrays Harry during the Horcrux hunt. You can find these on fanfiction.net by simply searching for 'betrayed Harry Potter fanfic'. Another source could be Archive of Our Own, where you might find 'betrayed' stories in various fandoms like Marvel or Star Wars.
In the '4 kunoichi gets betrayed fanfic', it could be that the four kunoichi are working for a noble cause. However, one of their own, due to jealousy of the attention the others get, decides to betray them. She spreads false rumors about them, making the whole ninja community turn against them. The four kunoichi have to prove their innocence and also figure out a way to deal with the traitor within their group.
One popular 'beca betrayed fanfic' might be the one where Beca discovers her friend has been spreading false rumors about her behind her back. It shows how she copes with the betrayal and tries to move forward.
I'm not sure specifically which 'chuck chuck betrayed fanfic' you're referring to. It could be a very niche or even a self - created concept within a particular fandom. If it's related to a known TV show or book series, you could try searching in the relevant fan communities. For example, if it's related to a sci - fi show, check the sci - fi fanfic sections. They might have something that fits the bill.
One good one might be where Kakashi is betrayed in a Naruto and Harry Potter crossover. He could be betrayed by a fellow ninja who has been influenced by dark magic. In this fanfic, Kakashi might have to use his ninja skills in the wizarding world to figure out the betrayal and clear his name.
One popular 'Harry betrayed' fanfic might be 'The Betrayal of Harry Potter' which delves into a scenario where his friends turn on him due to a misunderstanding. Another could be 'When Harry was Left Alone' where he discovers that the wizarding world has a hidden plot against him.