The protagonist is obviously an important character. Since he is the one banished from the hero party. There must also be characters in the hero party itself that play a role, like the leader of the party who might have made the decision to banish him. And then there are likely characters that the protagonist meets after being banished, such as new allies or enemies in his new journey.
Perhaps a scientist could become a hero in a pandemic novel. They might be the ones who discover a cure or develop effective prevention methods. They use their knowledge and skills to fight against the pandemic, often facing numerous challenges and setbacks along the way.
The protagonist, of course, is very important. His journey of being banished and finding his new place is central to the story. There's also likely to be characters he meets after being banished who play significant roles in his new life.
It could be a rogue demigod who has a vendetta against Percy. This demigod might have spread the false rumors that led to Percy's banishment in the first place, and now he wants to make sure Percy never returns. He uses his own powers and manipulates other demigods and monsters to achieve his goal.
The main characters would include the stepmom who has to navigate her new role. The hero, who is on a path of growth and heroism. Then there could be other supporting characters like the hero's friends or mentors. Maybe there's an antagonist who tries to disrupt the family or the hero's journey, which would also make that character important in the story.
Obviously, one of the main characters is the woman who becomes the hero's stepmother. And of course, the hero himself. There may also be the hero's father, who is the link between the stepmother and the hero.
Well, the protagonist is the woman who becomes the mother of the hero. She could be from a normal background, like a working - class woman or someone with an average life. The hero is another main character, and he might have some unique features, like being born with a special mark or having an innate ability. There could also be other characters such as the hero's father, who might play a role in the backstory, or the hero's friends who join him on his adventures, and of course, there could be villains who try to stop the hero from achieving his destiny, all of which interact with the hero's mom in different ways.
Since I haven't read the novel, I can't say for sure. But I assume the main character would be the mom who became the hero's mother. And of course, the hero themselves would be another important character.
There might be a mentor - like figure that the banished character meets on their journey. This character could be full of wisdom and strange quirks, making them stand out.
The protagonist who is banished is obviously important. He drives the story forward as he deals with his new life. There's probably a character who befriends him after the banishment, which is also a key character.