Who could be the main characters in 'Death Goes to School with Harry' fanfiction apart from Harry and Death?

Well, it could be about Death taking on a form that can attend Hogwarts with Harry. Maybe it's there to protect him in a more direct way than the usual magical means. It might interact with Harry's friends, causing some confusion and also some revelations about the nature of life and death in the wizarding world.

He could meet the main characters from Death City. For example, Maka Albarn and Soul Eater Evans. They could be initially cautious around Harry but then become friends as they realize his good intentions.

It could be a follower of the God of Death who misinterprets the God's will and tries to bring chaos to the wizarding world. They might see Harry as an obstacle to their plans and try to eliminate him.

There could be American wizard characters like an American wizard guide who shows Harry around the American wizarding world. This character might introduce Harry to new spells or magical techniques that are different from what he knows in Britain.

Hermione could be a main character. She might be the one who first notices the strange changes in Harry after he becomes friends with Death. She could try to research about this unusual friendship in the library, using her vast knowledge to understand the implications. Ron could also be important. He might be initially skeptical about Harry's new 'friend' but then come to accept it as he sees the positive effects it has on Harry and the help it provides in their fight against dark forces.

There could be the Dragonborn. If Harry is in Skyrim, he might cross paths with the Dragonborn, and they could either become friends or rivals depending on the situation.

Besides Harry, Ginny could be a main character. She might be interested in the sports aspect of the Egyptian school, like their version of Quidditch. And there could be a local Egyptian student who becomes friends with Harry. This student could have a deep connection to the history of Egypt and help Harry understand the significance of certain magical sites in the country. They could explore ancient temples together and face various challenges along the way.

Death, of course, would be a major character as it's training Harry. Maybe Dumbledore could also play an important role. He might be the one who initially guides Harry to this encounter with Death or acts as a moral compass during the training.

Perhaps Death is a being from a different dimension in this fanfiction. It exists outside the normal rules of the wizarding world and has the power to interfere when it deems necessary. It could have its own motives for helping Harry. Maybe it wants to study the unique magic that Harry possesses, or it could be that there is a prophecy that ties Harry's success to the stability of the multiverse, and Death is simply acting to preserve the greater good.

Hermione and Ron would likely still be main characters. Hermione would use her intelligence to help Harry understand his new identity and its implications. Ron, with his loyalty, would stand by Harry through any difficulties that come his way. There could also be Death himself, who might make appearances to guide or test Harry. And perhaps Dumbledore, as he always has a role in Harry's life in the wizarding world, could be involved in helping Harry navigate this new revelation.