Well, perhaps Pettigrew gets tired of living in fear under Voldemort. He might find a powerful magical artifact that has the potential to kill Voldemort. As he tries to steal it for himself, Voldemort discovers his plan. In the ensuing struggle, Pettigrew manages to turn the artifact against Voldemort and kills him. This would then lead to Pettigrew having to deal with the consequences, like facing the wrath of the Death Eaters who are still loyal to Voldemort.
Yes, there might be such fanfictions out there. Fanfiction writers often explore alternative storylines, and the idea of Pettigrew turning on Voldemort and killing him is an interesting and unexpected twist. It could involve Pettigrew having a change of heart due to some complex reasons, like realizing the true evil of Voldemort's ways or having a personal vendetta against him that overrides his loyalty.
The wizarding world would likely be in a state of shock and then celebration. People would start to see Azkaban in a new light, perhaps no longer as just a place of horror but also as the site where the great evil was finally vanquished.
After Harry kills Voldemort in the graveyard in the fanfiction, the magical balance might shift. With Voldemort gone, some of the dark magic that was prevalent might start to fade away. The Hogwarts School of Witchcraft and Wizardry could see a new golden age. New spells and magical theories might be explored as the fear of Voldemort no longer holds back the wizarding scholars. Harry himself might start to travel around the world to spread the news of Voldemort's defeat and also to learn more about different types of magic. His friends would also have new opportunities, like Hermione might be able to further her studies without the constant threat of Voldemort and Ron could finally relax and enjoy a more peaceful life at the Burrow.
One possible plot twist could be that while captured, Harry discovers a hidden power within himself. Maybe it's a new type of magic that he unlocks due to the extreme situation. This power allows him to not only break free from his captors but also gives him an edge over Voldemort. Another aspect could be that the capture was part of a plan all along, by Dumbledore or some other wise wizard, to deceive Voldemort and get Harry in a position where he can deliver the final blow.
One possible plotline could be that Snape discovers a hidden vulnerability in Voldemort. Maybe it's related to his Horcruxes. Snape, being the intelligent and resourceful character he is, figures out a way to destroy all of Voldemort's Horcruxes without Voldemort suspecting. Then, he uses his powerful magic skills, perhaps a combination of dark and light magic, to directly confront and kill Voldemort.
Perhaps in this fanfiction, Harry discovers some dark secret about the Order of the Phoenix or Dumbledore that makes him lose faith in the side he has always been on. This, combined with Voldemort's manipulation, could lead him to side with the Dark Lord. For example, if he finds out that Dumbledore has been using him all along without his full knowledge, he might be so disillusioned that he turns to Voldemort as an alternative.
A plot twist might be that when Harry goes to Voldemort, he discovers that Voldemort has a secret weakness. Maybe it's related to his family or some long - forgotten magic. Harry then has to decide whether to use this weakness against Voldemort or try to redeem him. This would add a whole new layer of complexity to the story. Another aspect could be that there are other forces at work, like a third - party wizard who is manipulating both Harry and Voldemort for their own gain, and Harry has to figure out who this is while dealing with Voldemort.
Well, it could be that in this fanfiction, Harry discovers some long - hidden truth about the wizarding world that makes him realize Voldemort's motives aren't entirely baseless. Maybe there's a prophecy misinterpretation that leads Harry to think they can work together to fix the wizarding world's problems.
In such a fanfiction, it could be that Harry Potter has been corrupted by a powerful and malevolent force. This force might have warped his sense of right and wrong. It could also be that the author wants to explore the extreme consequences of power and how it can turn a hero into a villain. For example, if Harry Potter was constantly taunted and mistreated by the wizarding community despite all he has done, he might reach a breaking point and lash out at everyone.
One possible consequence could be that he is immediately sent to Azkaban. Since he's a known traitor, the wizarding world would want to punish him severely for his crimes, which include betraying the Potters and framing Sirius Black.