Another possible character could be a human who befriends Percy without knowing his non - human secret at first. As the story progresses, this human might play a crucial role in helping Percy accept his true self. Also, there might be a group of hunters who are after non - human beings and Percy has to avoid them.
There could be other non - human characters like a wise old wizard who knows about Percy's true nature and tries to guide him. Maybe a shape - shifter who at first seems like an enemy but later becomes an ally.
There could be a wise old monster who acts as Percy's mentor. Maybe a female monster who becomes Percy's love interest. And of course, there would likely be some villainous monsters who oppose Percy's new existence and try to harm him.
His friends could be involved, like Annabeth. She might be mourning at the funeral and then be extremely surprised and happy when Percy shows up. Grover could also be there, and he'd probably be the first to give Percy a big, emotional hug.
Jason is likely to be another main character. Since he has his own set of skills and knowledge, he might have an interesting relationship with Percy in this story. Maybe he's a bit jealous at first of Percy's control over the ship, but then they end up working together really well. And of course, Piper could be there too. She might use her charm - speak abilities to help the crew communicate with any strange creatures they encounter during Percy's time controlling the Argo 2.
Grover can also be quite prominent. His loyalty to Percy remains a key factor. In some fanfictions, his connection to nature might be enhanced to better support Percy in his overpowered adventures. For example, he could be able to communicate with more powerful nature spirits to assist Percy in battles or quests.
Another possible main character could be a rival. A person who is always competing with Percy and who might use the discovery of her secret as a weapon against her. This would add a lot of conflict to the story.
Annabeth could be a main character. She might be trying to stop Percy from wanting to die. She could use her intelligence and her deep understanding of Percy to figure out what's wrong and try to talk him out of it. For example, she could remind him of all the good things they've been through together and all the people who need him.
There could be a strict but kind music teacher. This teacher sees Percy's potential and pushes him to practice harder and improve his skills. Another character could be Percy's best friend who is always there to support him during his musical journey, even when things get tough.
Grover could also be a main character. He could use his nature - related abilities to assist Percy when he wields the Blades of Chaos. For instance, he might be able to sense danger in the environment that Percy can then use the blades to face. Grover could also help Percy find his way in places where the Blades of Chaos' power might be affected by the surrounding nature.
There could be an old Alaskan native who becomes Percy's guide. He has a wealth of knowledge about the land and its spirits. He helps Percy understand the ways of the Alaskan wilderness.
Annabeth would be a likely character to help Percy. She is his close friend and has a sharp mind. She could use her intelligence to analyze the evidence against Percy and find the flaws in it. Also, Grover, with his ability to sense things, might be able to pick up on some clues that others miss.