Another possibility is that Hermione stumbles upon some new information about Dumbledore's family or personal history that completely changes her view of him. For example, if she learns that Dumbledore had some connection to a dark magic artifact or event in the past that he had been hiding, and that this connection had negative implications for the wizarding world. This discovery could fuel her desire for revenge as she feels deceived by his false image.
One factor could be a sense of being used. If Hermione discovers that Dumbledore had been using her intelligence and skills for his own secretive ends without her full knowledge, she might feel extremely angry and want revenge. For instance, if he made her unknowingly participate in a dangerous plan that put her or her friends at risk.
In fanfiction, Hermione wanting revenge on Dumbledore could be due to various reasons. One possibility is that she discovers some hidden secrets about his actions that she deems unethical. For example, if she found out that Dumbledore had been using students for some greater, yet morally ambiguous plan. However, this goes against the general perception of Dumbledore in the original series. Fanfiction often takes such unexpected turns to explore different character dynamics and plotlines.
Well, in some fanfictions, Dumbledore might want to punish Hermione if she goes against the school rules in a way that he thinks is particularly serious. For example, if she delves too deep into dangerous magic without proper authorization.
In a more extreme case in the fanfiction, Dumbledore might assign Hermione to a special project that is both difficult and dangerous as a form of punishment. For example, he could send her to study a group of cursed magical creatures in the Forbidden Forest. This would be a punishment that not only tests her skills but also her courage.
Dumbledore might be motivated by his over - arching plan to defeat Voldemort. He could see Hermione as a sacrifice that needs to be made. Maybe he believes that by betraying her, he can gain some crucial information from the enemy that will ultimately lead to Voldemort's downfall.
Well, it could be that Rumple discovers some past wrong Dumbledore did to him or his kind. Maybe Dumbledore once meddled in Rumple's magical affairs and now Rumple wants to make him pay. He could start by using his unique magic to create chaos in Hogwarts, like making the staircases go haywire or the portraits misbehave.
It could also be that Dumbledore has some secrets that he's afraid Hermione will uncover if she's left to her own devices. Hermione is known for her inquisitive nature. So, to keep these secrets hidden, he attempts to control her. For instance, if there are some hidden aspects of Hogwarts' history or certain faculty members that he doesn't want exposed, he might use control over Hermione to prevent her from delving too deep.
One possibility is that she has to move there due to some sort of magical experiment gone wrong at Hogwarts. The professors might think that living in a Muggle - dominated area like Privet Drive could help reverse the effects. So she ends up there, trying to figure out how to get back to normal while also dealing with the strange Muggles around her.
In fanfiction, it could be that Charlie has a more mature understanding of Hermione's intellectual pursuits. Ron sometimes struggles to keep up with Hermione's thirst for knowledge. Charlie, with his own expertise in his field, might be able to engage Hermione in more in - depth conversations, leading her to consider a relationship with him instead of Ron.
In a 'Harry Potter gets revenge on Dumbledore' fanfiction, Harry could find out that Dumbledore knew about certain threats to his life but didn't do enough to protect him. So, Harry decides to get revenge by undermining Dumbledore's influence at Hogwarts. He might start by convincing the other students that Dumbledore isn't as infallible as they thought. He could do this by revealing some of Dumbledore's past mistakes. Then, he could work on getting the school governors to question Dumbledore's leadership, gradually chipping away at his power and status within the wizarding community.
One possible plot could be that Hermione discovers a hidden family secret that reveals she is Dumbledore's sister. This leads to her having access to new knowledge and powers that Dumbledore left for her, which she uses to fight a new dark force in the wizarding world.