It could be that there are antagonists in the fanfic that play a role in Percy's decision to leave. They might be making the hunt too dangerous or corrupt. There could also be other hunters who have their own motives and reactions to Percy leaving, which could add more drama to the story.
Maybe there are some new characters introduced. They could be the ones who tempt Percy to leave the hunt, or they could be the ones he meets after leaving. Another character could be a mentor figure who gives Percy the advice to leave the hunt for his own good.
There could be his friends or comrades in the hunt. For instance, someone like Annabeth who might be affected by his leaving and try to convince him to stay.
Annabeth could be one of the main characters. She might be torn between staying with the gods and following Percy. Their relationship could be a central part of the story as she tries to convince him to stay or decides to go with him.
Artemis could be a major character. As the goddess associated with the Hunt, she would have a huge role. She might initially be skeptical of Percy's ability to protect the Hunt but gradually come to trust him. Thalia, who is part of the Hunt, would also be important. She has her own history with Percy and could be a key ally in the protection efforts.
Artemis is a must - as the goddess leading the Hunt. Her hunters, especially those like Phoebe, could be main characters. Phoebe could be curious about Percy and his blindness. She might be the one to first approach Percy when he's found. Another character could be Chiron. He could hear about Percy being with the Hunt and come to check on him. He could offer advice to both Percy and the Hunt, based on his vast knowledge of demigods. And then there's the Oracle. It could give some cryptic prophecy related to Percy's new situation with the Hunt, which would add an interesting layer to the story.
Obviously, Artemis. She is in charge of the Hunt, and her relationship with Percy would be central to the story. Then there could be Zoe Nightshade. She was a very important member of the Hunt in the original Percy Jackson lore. If Percy is adopted by the Hunt, she would have a big influence on him, either as a mentor or as someone who initially opposes his presence. And the wolf is also crucial. It could be a mysterious figure, maybe a messenger of the Hunt or a guardian of some sort, and it would be involved in Percy's journey every step of the way.
There could be an alien sidekick named Zorx. Zorx might be a small, furry creature with the ability to see in multiple spectrums, which helps Percy navigate through different planetary environments.
Annabeth could be a main character. She might be initially distrustful of Percy because of his mother but then come to see his true worth. Another could be Grover, Percy's loyal friend, who stands by him through all the difficulties. There could also be new characters, like a half - spider half - human hybrid who is Percy's distant relative and helps him understand his heritage.
Well, without actually reading the fanfic, it's hard to say for sure. But it could be his friends. In many fanfics, there are often sidekicks or best friends who play important roles. They might support Percy in his adventures or add some comic relief to the story.
There could be new characters introduced as well. Maybe other gods or demigods who have a particular interest in Percy's new - found godhood. They could either be allies or antagonists, depending on their motives and how Percy's new power impacts the existing power balance in the fanfic's universe.
Annabeth could be a main character. She might be skeptical at first about Percy's new ability to control Styx, but then she uses her wisdom to help him understand the implications and possible uses of it. For example, she could research ancient texts to find out if there are any hidden dangers or benefits to Percy's control.
Maybe Percy leaves the hunt because he has some personal issues to deal with. For example, he might have a family matter that requires his full attention. Or perhaps he has a different mission or goal in mind that conflicts with the hunt.