Who could be important characters in 'Harry Potter discovers his heritage fanfiction' aside from Harry?

Hermione would probably be there. She's Harry's best friend and always helps him in his adventures, so in a fanfiction about Harry discovering his heritage, she would be by his side, using her vast knowledge to help him figure things out.

One interesting plot could be that Harry discovers a hidden magical ability passed down through his heritage that no one in the wizarding world has seen before. Maybe he can communicate with magical creatures in a unique way, which helps him solve a big mystery in the wizarding world.

Hermione is often in these fanfictions. She might help Harry understand the more complex magical aspects related to his broomstick. For example, she could research ancient spells that were once used to enhance broomstick speed and try to apply them to Harry's broom.

Hermione would surely be involved. She could be Harry's research partner, helping him find relevant medical information in books and scrolls. Her intelligence and thirst for knowledge would be very useful in exploring new areas of medical magic. Another character could be Madam Pomfrey. She could be Harry's mentor, teaching him the basics of wizarding medicine and guiding him in his new role as a medic.

Dumbledore could play an important role too. Even though he's passed away in the original series, in fanfiction, his spirit or his past actions could be related to Harry's inheritance. He might have left some clues or instructions for Harry to find out about his true inheritance.

The supreme Mugwump himself could be a main character. He might have his own backstory, motives, and goals that drive the story forward.

One possible main character could be a Martian elder who takes Harry Potter under their wing and helps raise him. This Martian elder could have special knowledge about the planet and its hidden magic that they pass on to Harry.

Well, first off, Ursula is an obvious main character as she is related to Harry in this fanfiction. Then there's Hagrid. He has always been there for Harry and would likely play a role in helping Harry deal with this new situation. Neville could also be an important character. He might be one of the few who initially believes in Harry and doesn't immediately turn his back on him because of his new identity. And then there are the Weasley family members. They might be a bit hesitant at first but would eventually come around to help Harry as they have always been a big part of his life at Hogwarts.

Maybe some of the Hogwarts professors could be involved. For example, Professor McGonagall could be concerned about Harry's new situation and offer her guidance. There could also be some descendants of previous island owners or caretakers who have their own interests in the island. They could either be friends or foes to Harry, adding more complexity to the story. Additionally, some magical creatures native to the island could be almost like characters themselves, interacting with Harry in unique ways.

Obviously, Harry himself is the most important character. His journey of learning about his heritage is at the core of the story.