Definitely Percy Jackson. Then, his friends from Camp Half - Blood such as Nico di Angelo could be common. Nico's powers and his relationship with Percy could add interesting dynamics to the fanfiction. Also, Chaos, as Percy's newfound parent, is likely to be a major character, and other primordial entities might also make appearances to interact with Percy in his new role as the son of Chaos.
In many 'Perseus Jackson Son of Chaos' fanfictions, a recurring and exciting plotline is Percy's journey of self - discovery. As the son of Chaos, he is not only more powerful but also has a different perspective on the world. He may start to question the rules and hierarchies he grew up with. For example, he might find that the way the Olympians govern is not as perfect as he once thought. This could lead to conflicts with the gods or his former allies. He also might discover hidden secrets about his own past and the origin of the demigod world, which could change everything he knows.
Aside from Percy himself, Hermes is obviously a common character. Annabeth might also be there, as she is often Percy's friend and ally. Grover could make an appearance too, since he is Percy's long - time friend. There could also be other demigods from the Hermes cabin who interact with Percy, like Luke (although his story might be different in this fanfiction context).
Nico di Angelo could be a significant character. Given his own complex relationship with the gods and his powers over the Underworld, he could have an interesting dynamic with Percy as the son of Hestia. The goddess Hestia herself is likely to be a prominent figure in these fanfictions. She could be guiding Percy from afar or directly interacting with him, giving him tasks or imparting wisdom about his new role and the importance of her domain.
Another main character could be Chiron. He has always been an important figure in Percy's life. In this fanfiction, he might be the one who first discovers Percy's connection to Chaos and tries to guide him. Or he could be struggling to understand how to deal with Percy's new situation, especially if Percy's powers start to have unforeseen effects on Camp Half - Blood.
Percy Jackson is definitely a main character. He's the one at the center of the 'son of chaos' concept. Then there are his friends from Camp Half - Blood like Annabeth. She might be involved in trying to understand Percy's new situation or helping him in his new adventures. Grover could also be there, being Percy's loyal friend as always.
A prevalent theme is isolation. In many fanfictions, Percy feels alone because of his strange heritage. He doesn't quite fit in with the normal demigods. Also, the theme of destiny often comes up. He has a special destiny due to his parents that he is constantly striving to fulfill.
Power and identity are common themes. Percy as the son of Chaos has new powers, and he has to figure out how to use them while still being himself. Another theme is relationships. The harem aspect means there are multiple complex relationships to explore.
Well, obviously Perseus Jackson is one of the main characters. He is the hero around whom the story revolves. His friends, like Annabeth Chase, are also likely to be main characters. Annabeth is smart and often helps Perseus with her strategic thinking.
In some fanfictions, Percy Jackson is indeed portrayed as the true son of Chaos. Writers often take creative liberties to explore new storylines and character developments. This idea can lead to very interesting and unique plot twists, such as Percy having powers beyond what we see in the original series.
Obviously, Percy Jackson is one of the main characters as he is the son and heir of chaos in this fanfiction. His friends from the original series like Annabeth Chase could also be main characters. They would likely play important roles in supporting Percy on his new journey and dealing with the implications of his new status.