One consequence could be that memories are altered. People might forget certain events that happened before the time reset. For example, Voldemort's followers may not remember some of their evil deeds if those events are wiped out by the time reset.
The relationships between characters can change significantly. Harry might have a chance to form different relationships with his friends or enemies. He could use his knowledge from the previous 'timeline' to avoid past mistakes in his friendships. For instance, he might be able to prevent a rift between Ron and Hermione that happened before the time reset. Also, in the new timeline, the power dynamics in the wizarding world could shift. Some families or groups that were powerful before may lose their influence, while others might gain it because of the changes brought by the time reset.
The course of magical education at Hogwarts could be different. New spells and magical theories might be introduced or old ones forgotten. Teachers could also be different. For example, if a certain teacher died in the previous timeline but the time reset changed the events leading to their death, they could still be teaching at Hogwarts. This would have a big impact on the students' learning experience, like Harry and his friends. And the overall political situation in the wizarding world could be completely different, with new laws and regulations being implemented as a result of the changed history caused by the time reset.
Well, in some fanfictions, it could be due to some ancient magic tied to Harry. Maybe his death breaks a certain magical seal or spell that was set long ago to keep the time in a loop until a certain condition (like Harry's survival) is met.
Well, it would have a huge impact on the wizarding world as a whole. The Ministry of Magic would be in an uproar. They had high hopes for Harry and his role in the future of the wizarding community. His death could also lead to a change in the way Hogwarts approaches the Triwizard Tournament in the future. There would be a lot more safety regulations and restrictions. And his death would leave a big emotional void in the hearts of those who knew him, like Hagrid who had a special bond with Harry.
The consequences can be chaotic. It might lead to altered timelines. People could end up in the wrong era or at the wrong moment in history, changing the course of events in the wizarding world.
In many fanfictions, Harry discovers a hidden ability within himself to stop time. This could be related to his connection with some ancient magic. Regarding the consequences, it could put him in a moral dilemma. If he uses this power to gain an advantage in a wizard duel, it might be considered cheating. Moreover, the wizarding world's time - keepers, like the Department of Mysteries, might take notice and try to stop him.
It could be due to some kind of self - sacrifice he made in a previous battle. For example, he might have used a very dangerous spell that had a side - effect of slowly killing him to save his friends or the wizarding world.
There could be unforeseen magical consequences. Time - traveling is a tricky business in the wizarding world. By changing Sirius' fate, Harry might accidentally create new problems. For example, the balance of magic in certain areas could be disrupted. There might also be changes to the Hogwarts' community. Students and teachers who were affected by Sirius' situation in the original timeline might act differently.
A possible plotline is that Harry accidentally discovers the time - controlling power while exploring an old, forgotten part of the Hogwarts library. He then has to figure out how to use it without disrupting the fabric of time too much.
One possible storyline could be that in a final battle against Voldemort, Harry sacrifices himself in a way that no one could reverse. For example, he might use a powerful spell that requires his life force to destroy the last of Voldemort's Horcruxes. Another could be that he succumbs to a dark curse that was placed on him long ago, which was dormant until a certain event triggered it. Maybe a character that was thought to be an ally actually turned out to be a double - agent and cast a fatal spell on Harry.
It could also affect their relationship with other family members. For example, Ginny might step in to mediate between them, or it could cause tension within the family as a whole. If Albus feels unjustly yelled at, he might turn to other family members for support, which could create some family drama.
If Harry Potter refuses to help fanfiction, it might result in some fanfiction losing a bit of authenticity in the eyes of fans. Since Harry is such an iconic character, his absence of support could make some people view certain fanfictions as less legitimate. However, it could also encourage fanfiction writers to develop their own unique voices and storylines without relying on the character's 'approval'.