With Draco Malfoy, instead of the usual rivalry, Harry might be more dismissive. Raised by the founders, he would have a stronger sense of self - worth and not be as affected by Draco's taunts. He might even pity Draco for his narrow - minded views, which are in contrast to the broader perspectives he's gained from the founders.
His relationship with Dumbledore would be complex. Dumbledore is seen as a great wizard in the normal series, but Harry, raised by the founders, might question Dumbledore's actions more. He could have different ideas about how Hogwarts should be run and how to deal with the threat of Voldemort, based on what he's learned from the founders.
His relationship with Ron and Hermione would be very different. Since he's been raised by the founders, he might be more aloof from the typical Gryffindor camaraderie. He could see Ron's insecurities in a different light, perhaps being less patient with them. And with Hermione, he might be more critical of her book - learning approach as he's been taught by the founders themselves.
If Harry was raised by the founders in fanfiction, his relationship with his enemies would also change. Voldemort might see him as an even greater threat because of the knowledge and power he gained from the founders. And Harry might not have the same relationship with Dumbledore. He would be more independent and rely more on the teachings of the founders rather than Dumbledore's guidance.
Obviously, Harry Potter himself. Then there would be the four founders: Godric Gryffindor, Salazar Slytherin, Rowena Ravenclaw, and Helga Hufflepuff. They could be present in some form, either as ghosts or through memories guiding Harry. Dumbledore might also still play a role, perhaps as a sort of mediator between the modern world and the founders' teachings that Harry is receiving.
His relationship with Hermione would be very different. Instead of being friends, they might be enemies at first. Since he was raised by Death Eaters, he might look down on Hermione as a Muggle - born. But as he gets to know her better, he could start to question his beliefs.
One possible plot twist could be that the founders' different teaching styles clash when raising Harry. For example, Salazar Slytherin might be more strict about pure - blood heritage, while Helga Hufflepuff would focus on his kindness. This could lead to internal conflicts within Harry as he tries to balance their different expectations.
His friends might be initially shocked. Hermione would be super curious and want to research all about it. Ron might be a bit jealous at first, but then come around. Their adventures would be different as Harry would have new insights from the founders.
There could be. Fanfic writers often come up with unique concepts. The founders' trains might be used to transport students in a time long before the Hogwarts Express we know. It could be a way to show a different side of the founders' era, with different magical technologies or traditions associated with these trains.
It could be really interesting. Maybe Harry would grow up with the values and knowledge directly from the founders. He might be trained in magic in a more traditional and pure way, like how the founders would have taught. For example, he could learn advanced spells earlier and have a deeper understanding of Hogwarts' history and secrets from the start.
If Harry's wand were to fuse with another, say Hermione's, it could create a stronger bond between them. They would have to rely on each other more to understand the new powers of the wand.
In addition to the trio, there could be characters like Professor McGonagall. She would surely notice the changes in Harry and might try to guide him. Also, the ghosts of the founders themselves could be considered main characters in a sense. Since Harry is possessed by them, they would have a significant influence on the story, perhaps communicating with Harry or causing events to unfold around him.
With Dumbledore, it would be a complex relationship. Dumbledore would be cautious yet intrigued by Harry. He would want to guide Harry away from the potentially dark path that his Nathrezeim upbringing could lead him to. Harry, on the other hand, might be resentful of Dumbledore's interference at first.