In such a fanfiction scenario, it would completely颠覆 the original story. Harry would be on the side of evil, which means he might be involved in dark magic practices and attacking those he once considered friends and allies. It would be a very dark and扭曲的 version of the Harry Potter universe.
If Harry Potter becomes a Death Eater in fanfiction, his relationship with his friends would be shattered. Hermione and Ron would likely become his enemies. Also, Hogwarts would no longer be a safe haven for him as the Death Eaters are against the school's values. He would probably have to abandon his previous beliefs about love and friendship, which were the foundation of his fight against Voldemort in the original story.
In such a fanfiction, Harry Potter might start to embrace the Dark Arts. He could abandon his friends at Hogwarts and join forces with Death Eaters. His actions would likely shock the wizarding world, and he would become a hunted figure by those who still oppose Voldemort and his followers.
Well, he might be really confused at first. Harry comes from a world of magic with its own set of rules, and Soul Eater has a very different kind of magic system. He'd probably be intrigued by the unique characters and the dark - yet comical - tone of Soul Eater. Maybe he'd start comparing the ways of using magic in his world to that in the fanfiction.
The plot could develop in a very dark way. Harry might start hunting down the Order of the Phoenix members. He would be using his knowledge of the good side to help the Death Eaters. For example, he could lead them to the secret passages in Hogwarts.
In some fanfictions, if Harry Potter becomes a warlock, he might gain even more powerful magic. He could have greater control over spells and be able to perform magic that was previously thought impossible. For example, he might be able to manipulate time in a more complex way or have the power to instantly transport himself anywhere in the wizarding world without the need for a Portkey or Apparition.
If Harry Potter becomes god in fanfiction, he might completely reshape the magical world. He could rewrite the laws of magic, perhaps making it more accessible and less dangerous. He could also bestow extraordinary gifts upon his friends. Hermione might gain the ability to instantly understand and master any spell or bit of knowledge, and Ron could become an unbeatable warrior with superhuman strength in the face of any danger.
In this kind of fanfiction, Harry might teach his children magic in a very different way from how he was taught. He would be extremely protective, having faced so many dangers himself. Maybe he'd pass on the lessons he learned from his own battles, like the importance of friendship and courage.
If Harry Potter becomes the Joker in fanfiction, he would probably start to question all the values he once held. The Joker is all about subverting order, so Harry might begin to undermine the Ministry of Magic and other institutions. He could use his knowledge of magic to play cruel pranks on people, not the innocent kind of pranks he used to do. His Gryffindor courage could be twisted into a reckless disregard for the safety of others.
If Harry Potter becomes a Jedi, he would likely combine his existing magical skills with Jedi abilities. His Patronus charm could be enhanced by the Force, becoming an even more powerful protective entity. He might use his wand as a sort of lightsaber hilt, channeling the Force through it for unique combat moves. His ability to apparate could be refined with Jedi - like teleportation skills. Also, his knowledge of the wizarding world's dark magic could help him better understand the dark side of the Force and avoid its temptations.
If Harry Potter becomes a Lamia in fanfiction, his relationships would change drastically. His friends might be both intrigued and a bit scared at first. He would have to adapt to his new form and its characteristics. For example, he may need to learn how to control any new instincts that come with being a Lamia. Also, his role in the fight against Voldemort could be completely different. Instead of using a wand in the traditional way, he could use his Lamia - related powers to combat the dark forces.
If Harry Potter becomes a demon in fanfiction, his relationships would be severely affected. His friends like Ron and Hermione would be very confused and possibly afraid of him. They might try to find a way to reverse the transformation. And Hogwarts itself would be in chaos. The teachers would be divided on how to deal with him, some might want to help him while others might see him as a threat to the safety of the school.