There could also be new characters emerging. For instance, the children of the main characters could become important. Or perhaps some previously overlooked characters like Luna Lovegood could step up and play a significant role in the post - battle wizarding world. She might start a movement to promote more acceptance of different magical beliefs and oddities.
Obviously, Harry Potter himself would still be a central character. He would be dealing with the aftermath of the battle, like post - traumatic stress or trying to bring about positive changes in the wizarding world.
Hermione Granger would also be a key figure. She could be using her intelligence to help in the reconstruction of the wizarding world. Maybe she's working on new laws to protect house - elves or researching new spells. Ron Weasley would be by her side, providing support and also being involved in the Ministry of Magic's new initiatives.
Obviously, Harry Potter himself. He would be a central figure as he was the key in the battle against Voldemort. His friends Ron and Hermione would also be important. They've been with him through thick and thin. Neville Longbottom would be another likely main character. His heroics in the final battle would give him a significant role in the post - battle world. Ginny Weasley too, as Harry's girlfriend and a brave witch in her own right.
Obviously, Harry Potter is one of the most important. His role as the Chosen One is central to the final battle. Hermione Granger also plays a crucial part with her intelligence and knowledge of magic. Ron Weasley too, as he provides support to Harry.
The key characters could be Harry's muggle relatives. The Dursleys have been his legal guardians in the muggle world for a long time. They might be fighting to keep Harry in their home. On the wizarding side, Hagrid could be important. He was the one who introduced Harry to the wizarding world. He might step in to ensure Harry is placed in a proper wizarding family or environment. Also, Hermione and Ron could play a role. They are Harry's best friends and would surely fight for Harry to be in a place where he can be happy and learn magic freely.
In many fanfictions, after the final battle, Harry might focus on rebuilding Hogwarts. He could use his influence to make it a more inclusive and modern place of magic learning, with new courses perhaps on Muggle technology and its integration with magic.
They could go on a quest to discover hidden magical artifacts. For example, they might search for ancient spells that were lost during the war. This would not only be exciting but also help in the restoration of the wizarding world's magical knowledge.
Obviously, Harry Potter would be one of the main characters since he's the one doing the split. Hermione would probably also be involved. She might be the one to research why Harry suddenly has this strange new ability or how to control it.
Newly discovered magical families could rise to prominence. These families might have been in hiding or just not known before, but now they play a crucial role in the wizarding world of 1000 years later. Their members could be the main characters, bringing in fresh perspectives and magical abilities that were previously unheard of.
Hermione might also be a main character. Her intelligence and knowledge of magic would be invaluable in dealing with whatever the weapon in Gringotts is. She could be the one to figure out how to unlock the secrets surrounding the weapon, like deciphering ancient runes or understanding complex magical texts related to it.
Harry Potter himself would likely be a central figure. He has a history of fighting against dark forces and would probably step up to try and maintain order. Hermione would also be important as she is intelligent and could come up with plans to deal with the situation. Ron, with his loyalty and courage, would be by their side.
Hermione could be a major character. She would be really helpful with all her knowledge, maybe helping Harry with the care of the magical creatures and coming up with ways to educate the visitors. Ron might also be there, perhaps handling the more physical tasks around the zoo like building enclosures for the larger creatures.