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.
One idea could be exploring the secrets hidden in the graveyard that are related to Hogwarts' founders. Maybe there are ancient spells inscribed on the tombstones that could be a key to a new mystery at the school.
The main antagonist could be a dark wizard who has made the graveyard his lair. He uses the dark energy from the tombstones and the restless spirits there to power his dark magic. Harry stumbles upon this wizard's activities and has to stop him.
Most likely, Voldemort would remain the main villain. Without Harry to stop him, he would be free to carry out his evil plans unopposed.
It could be a new character, like an assassin from a far - off land who comes to Hogwarts under false pretenses. They have their own set of skills and motives that are different from the regular characters in the Harry Potter series.
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 Muggle - born wizard could be the main character. They are used to the Muggle concept of hairdressing but also want to incorporate their new - found magic into it. This character would be constantly trying to bridge the gap between the two worlds in their salon, creating a unique blend of Muggle and wizarding hairdressing styles.
In one fanfic, Gabrielle gets involved in an international wizarding competition that is not the Triwizard Tournament. This competition tests different magical abilities, and Gabrielle shows her courage and determination as she competes against some of the best young wizards from all over the world. It's a story of her growth and self - discovery.
Obviously, Harry Potter himself could be the main character. Given his adventurous nature, he would be a great fit to incorporate parkour into his already impressive list of skills. He could use parkour to explore new areas of Hogwarts or to escape from dangerous situations.
Perhaps Accelerator from the railgun universe could be the main character. He has his own set of abilities that would be very interesting to transplant into the Harry Potter world. He might initially be seen as a threat due to his powers but then end up using them to fight against a common enemy, like a new dark wizard or a powerful magical creature that has gone rogue.
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'.