I'm not sure specifically as there are many fanfictions with that theme. It could be about a character getting revenge on their enemies in the Harry Potter universe, perhaps a student getting back at a bully like Draco Malfoy, or a wizard seeking vengeance against a dark wizard. There are countless creative ways this could be explored in fanfiction.
The theme of betrayal also frequently appears. In many 'Harry Potter's Revenge' fanfictions, Harry has been betrayed by someone close to him, like a friend or a mentor. His revenge is then not just about getting back at that person, but also about restoring his own sense of self - worth and trust. He might go to great lengths to expose the betrayal and make the betrayer face the consequences, which can lead to some very intense and emotional storylines.
One interesting 'Harry Potter revenge fanfiction' might be where Harry gets revenge on the Dursleys for years of mistreatment. He could use his magic in creative ways to make them understand how cruel they were. For example, he might make them experience the same isolation he felt in the cupboard under the stairs.
One popular 'revenge Harry Potter fanfiction' might be those where Harry gets revenge on the Dursleys for their mistreatment. In some fanfics, he uses his magic in clever ways to make them realize how wrong they were. For example, he might expose their lies to the neighbors in a magical but non - violent way. Another type could be Harry getting revenge on the Death Eaters in a more brutal fashion than in the original books, perhaps using dark magic he learned from some hidden source. However, it's important to note that these often deviate from the original themes of the Potter series.
Hermione would be a likely supporter. She is always loyal to Harry and if he presented her with evidence of Dumbledore's wrongdoings, she would probably side with him. She has the intelligence to help Harry strategize and find ways to expose Dumbledore. For example, she could use her research skills to dig deeper into Dumbledore's past.
In such fanfiction, usually the character uses a time - turning device or some magical spell. They then travel back with the intention of revenge. For example, if it's Harry, he might go back to when Voldemort was still a student at Hogwarts to stop him before he becomes a dark wizard. He could use his knowledge of the future, like knowing about the Horcruxes, to defeat Voldemort early and get revenge for all the lives lost in the original timeline.
One common theme is power dynamics. When Harry travels back in time to take revenge, he often has to deal with the power structures in the wizarding world that were against him before. For example, he might have to outwit the Death Eaters or the Ministry of Magic who were once obstacles.
Perhaps in this fanfiction, Harry discovers some dark secret about the Weasleys that he believes endangers him or the wizarding world. His revenge could then be to expose this secret in a way that embarrasses the family. He might use his influence and knowledge to make sure the Weasleys are shunned by some in the wizarding community.
You can try some popular fanfiction websites like Fanfiction.net or Archive of Our Own. Just search for 'the best revenge Harry Potter' on their search bars, and you should get a list of relevant fanfictions.
Another option is to join Harry Potter fanfiction groups on platforms like Goodreads. Members of these groups often discuss and exchange their favorite fanfictions. You can ask for recommendations for 'Harry Potter revenge fanfiction' within the group, and they might be able to point you to some hidden gems that you wouldn't find otherwise.