Draco Malfoy would be a likely character. Given his Slytherin status, he would likely have a complex relationship with Percy. He might start off as hostile, seeing Percy as an outsider, but then they could end up having to work together for some reason.
Hermione Granger could also interact with Percy. She would be curious about his different abilities and background. She might try to study him like she does with new magical things, and they could become friends as Percy respects her intelligence and she respects his skills.
Well, Annabeth would definitely be one. She's always been by Percy's side, and in this fanfiction, she might be a bit worried about Percy being the champion of Nyx. She could be trying to help him while also being cautious of Nyx's motives.
One interesting plotline could be Percy having to deal with the Slytherin values while still holding onto his own heroic nature from the Percy Jackson series. Maybe he has to face prejudice from some Hogwarts students who are suspicious of a 'half - blood' being the heir.
Probably other demigods would interact with Percy. Maybe some demigods who are in need of a more stable influence in their lives would seek out Percy. Also, characters like Grover might find Percy in Hestia's care and there would be a reunion. And the gods and goddesses who are associated with the concept of home or family in Greek mythology, like Demeter, could also have interactions with Percy.
Definitely Annabeth. She and Percy have a strong relationship, and Hera's possessiveness would surely disrupt that. Also, other demigods at Camp Half - Blood could interact with Percy. They might sense that something is off with Percy due to Hera's actions and try to help him or at least figure out what's going on. And of course, the gods themselves might interact with Percy. Some gods might side with Hera, while others might oppose her possessiveness over a demigod like Percy.
The gods, especially Zeus. He has always been a bit suspicious of Percy. In fanfiction, he could easily be written as spreading lies about Percy to the other gods and demigods, leading to everyone turning against him. Also, some new characters introduced in fanfiction might be the ones who start the chain of events that lead to Percy's all - around betrayal.
Grover might also be involved. His ability to sense emotions and his connection to nature could play a role. He could be the one to initially sense Padme's arrival or help her understand the more magical and nature - related aspects of the Percy Jackson world, like the power of the gods and the spirits of the forest.
In most Percy Jackson canon, there is no relation to Thor. However, in fanfiction, anything can be possible. It could be that the author has created a unique crossover where Percy Jackson has some connection to being the heir of Thor, perhaps through some magical or divine intervention that the fanfic writer has dreamed up.
Yes, there are quite a few. You can find them on popular fanfiction platforms like FanFiction.net or Archive of Our Own. Some writers explore how Percy's character traits would interact with the Slytherin house values, creating really interesting and unique stories.
Percy himself, of course. Given his leadership skills and powerful abilities, he would be the first to step up and face the Pillar Men. His ability to control water could be a great asset or a hindrance depending on the situation.
In some fanfictions, Hermes interacts with Percy as a mentor. He might offer advice on how to deal with other gods or mythical creatures. For example, he could tell Percy the weaknesses of a particular monster. In other stories, he may be more of an enigma, his actions and words being hard to decipher. Sometimes, Hermes and Percy form an alliance, like when they have to face a common threat together.