Hermione Granger might also be a common character in such fanfictions. Given her intelligence and the times she has been in dangerous situations, there could be scenarios where someone owes her a life debt. For instance, a character she saved from a dark wizard might then be bound by a life debt to her, and their relationship could be explored in the fanfiction.
There could also be characters like Dumbledore, even if in spirit or through memories. His wisdom might have influenced Harry's understanding of life debts, and his past actions could be related to debts that Harry is now calling in. And then there are the characters who owe Harry their lives. This could include Neville, who Harry has saved on multiple occasions, and their relationship could be further explored in the context of the life debt.
Obviously, Harry Potter himself is the central character. Others could include Ron and Hermione, who have been by his side through many life - threatening situations and might also be in debt to him in some way, for example, if Harry saved them from a particular dark spell during a battle. Also, Neville Longbottom could be involved as Harry saved him from Voldemort during the Battle of Hogwarts.
Harry Potter himself is often involved. He might be the one to encounter the first signs of inflation, whether it's a magically inflating potion or an enchanted object. His friends, like Ron and Hermione, are also likely to be part of the story, helping him figure out what's going on.
Ron Weasley could also be a key figure. He might be Harry's loyal friend as always, standing by his side during all the changes that Harry is bringing about in the wizarding world as a god. And there could be new characters introduced as well, perhaps other gods or magical beings that interact with Harry in this new fanfiction realm.
In some cases, Albus Dumbledore could play an important role. His wisdom and power in the wizarding world would make him a key figure in any situation where the two different universes collide. He might be the one to first discover Alexstrasza's presence and figure out how to make use of her abilities in the fight against the dark forces in the Harry Potter world.
Obviously, Harry Potter himself is always a main character. He is the one most directly associated with the concept of death in the original series, what with his parents' death and his multiple near - death experiences.
Ron Weasley could be another main character. He might be initially skeptical about the piano's magic but then be amazed when he sees the extraordinary things it can do. Maybe he accidentally discovers a new function of the piano while fooling around with it in the Gryffindor common room.
Harry Potter himself could be one of the main characters in such fanfiction. Maybe he gets an automail limb after a particularly dangerous encounter with Voldemort. Hermione might also be involved, using her vast knowledge to help understand and improve the automail technology within the wizarding context.
Well, of course, Harry Potter himself is often the central figure. He's usually the one who discovers the amulet or is tasked with dealing with its powers or secrets. Hermione Granger also frequently appears, using her vast knowledge to help Harry understand the amulet.
Harry Potter himself is often involved. He might be the one to discover a mysterious egg or be tasked with protecting it. Hermione Granger could also be a main character, using her vast knowledge to figure out the nature of the eggs. Ron Weasley might be there too, providing some comical relief while also helping with the situation.