Jason's jealousy might initially make him act out in negative ways. He could be bitter towards Percy and Thalia, which would isolate him from them and others. But as the story progresses, he might realize that his jealousy is unfounded and start to change for the better, learning to be more confident in himself.
The jealousy can create conflict. Jason might start to act out, causing rifts between himself and Percy or Thalia. This can lead to different story arcs, like a rivalry developing. For instance, he could try to undermine Percy's actions or try to get closer to Thalia in a way that seems forced, which drives the plot forward as other characters react to his behavior.
The jealousy could lead to a split in the group. If Jason is constantly jealous, he may distance himself from Percy and Thalia, which would change the group dynamics. This could then lead to new alliances and rivalries within the fanfiction. Maybe Jason teams up with other characters who also feel left out because of Percy and Thalia's popularity.
It can add a lot of drama to the story. For example, Jason's jealousy might lead to him making rash decisions. He could try to compete with Percy and Thalia in a way that causes problems for their group. This might create conflicts that they have to resolve, making the story more interesting.
Well, it could be that in the fanfiction, Percy and Thalia are both really popular and well - liked among their peers. Jason, on the other hand, might feel overshadowed by them. He's jealous because they seem to get all the attention and admiration, while he feels like he has to struggle more to be noticed.
Well, in this fanfiction, Jason's jealousy could be shown through his actions and words. He may make snide remarks about Percy's power. Maybe he tries to undermine Percy's achievements. He could also be seen avoiding Percy because seeing him use his powers makes Jason feel inferior. Like when they are on a quest together, Jason might not cooperate as well as he should just because he's envious.
Jason might show his jealousy through subtle actions like avoiding Percy during group activities or making snide remarks about Percy's powers when others are around.
In the fanfic, it could be that Percy and Thalia have a certain level of trust and understanding that Jason lacks with either of them. For example, they might communicate in a way that Jason wishes he could with them. Percy's relationship with the gods, especially Poseidon, and Thalia's connection to Zeus might make them a more formidable and enviable pair in Jason's eyes. He may be jealous of the power dynamics and the way they interact within the story.
Annabeth might be annoyed. She's very perceptive, so she quickly realizes Jason's jealousy. She'll probably tell him directly to stop acting childish and respect her relationship with Percy.
The fanfiction might develop it through relationships. Say, Jason becomes closer to a group of characters that Percy wants to be part of. Percy then feels left out and his jealousy towards Jason intensifies. There could also be public events where Jason is praised and Percy is not, which is a common way to build up this jealousy plot.
It can create conflict. For example, Jason's jealousy might lead him to challenge Percy to a duel or some sort of competition. This then drives the plot forward as the other characters have to deal with the fallout of their rivalry.