It could be a young witch or wizard who is a transfer student to Hogwarts. They would be the main character as they try to adapt to the new environment and in the process, discover a magical mystery that sets them on a journey.
It could be about a new student at Hogwarts who discovers a hidden magical ability and embarks on a journey to uncover its origin. This journey might lead them to encounter forgotten spells, mysterious creatures, and make new friends along the way.
Perhaps it could be an older version of one of the main characters from the original series. For instance, an adult Harry Potter who has become a master of certain types of magic and is now on a new adventure. He could be traveling to different parts of the wizarding world to teach or to learn more advanced magic techniques. Another possibility is that it could be a character like Dumbledore in his younger days when he was on his own journey to become the great wizard he was known to be.
Another possibility is that it's a descendant of an ancient wizarding family. This character has been sheltered from the wizarding world until they discover their second magical core. Their family's secrets and history could be intertwined with the nature of this second core, and they have to navigate the wizarding world while also uncovering their family's past.
Neville would also make an excellent main character. He has a natural affinity for plants, and magical creatures are not that far off in the wizarding world. He could be the one to discover a new way to care for ailing magical creatures, perhaps using his knowledge of herbology. For example, he might find a plant that can cure a disease that's been affecting the unicorns in the forest.
It could be a new character, like a young Auror who has been assigned as an inspector. He would be fresh out of training and eager to prove himself at Hogwarts. He might be a bit naive at first but quickly learns the ropes and uncovers some interesting things about the school.
It could be a young witch who is just starting to explore her magical abilities outside of Hogwarts. She takes on a babysitting job to earn some extra money and ends up having all sorts of magical adventures with the kids she babysits.
A new character could be the main character. For instance, a Saiyan who has been transported to the Harry Potter universe. This character would have to navigate the strange new world of magic while also dealing with their own Saiyan instincts and powers.
It might also be a descendant of one of the well - known characters from the Harry Potter series. For example, a grandchild of Sirius Black who inherits his rebellious spirit and uses it to fight against the new dark forces as the 'darkslayer'.
A new student at Hogwarts could be the main character. They might be a bit of an outcast and find solace in the graveyard. There, they stumble upon a mystery that no one else has noticed before, and it becomes their mission to solve it. This would be a great way to introduce a fresh perspective to the Harry Potter fanfic world.
It could be a long - lost relative of Harry Potter. Maybe a cousin who was hidden away for some reason and now discovers their magical heritage. They could have a different personality from Harry, like being more shy and studious but still having a great sense of justice.