One possible reason could be that his friends wrongly accused him of something major. For example, if they thought he was secretly working for an enemy and didn't give him a chance to explain. Another reason might be that the gods themselves turned against him unjustly, perhaps because they feared his growing power and influence. This could make Percy feel so alone and betrayed that he decides to join Chaos as a form of revenge or to find a new place where he is accepted for who he is.
After joining Chaos, Percy's character evolves into a more complex one. He is no longer the naive hero he once was. He gains a new sense of purpose. With Chaos, he might be involved in more dangerous and morally ambiguous situations, which forces him to re - evaluate his values. He may become more independent and self - reliant, relying less on the support he used to get from his old friends and more on his own skills and the new allies he finds in Chaos.
One common theme is the fish - out - of - water experience. Percy is used to the world of demigods and suddenly finds himself in a completely different and chaotic place. Another theme is self - discovery. In the chaos, he often has to reevaluate his own powers and identity.
It could be a jealous friend. Maybe another demigod who is envious of Percy's powers or his popularity among their peers. This friend might see an opportunity to get Percy out of the way and so betrays him.
Well, perhaps Percy could be disillusioned with his current situation in his normal world. He might see the chaos army as a way to break free from the constraints he's felt. He could start off as an outsider in the chaos army, having to prove himself.
If Percy Jackson joins Chaos in fanfiction, it would likely change his entire perspective. He's used to the world of Greek gods and demigods. But in the realm of Chaos, there are no such clear - cut rules. He could be sent on wild adventures across different dimensions. He might have to face enemies that are far more powerful and unpredictable than anything he's encountered before. And his relationships with his friends from Camp Half - Blood would also be put to the test as he becomes something more than just a demigod.
Well, perhaps Percy is betrayed by his friends or allies who he thought he could trust. This betrayal could be due to jealousy, a misunderstanding, or someone's hidden agenda. As a result, Percy feels so hurt and angry that he decides to join the Hunt. In the Hunt, he might find a new sense of purpose, new friends who understand his pain, and he could start to train hard to become a more powerful fighter. He may also seek revenge against those who betrayed him.
Obviously Percy is one of the main characters. There might also be the leaders of the chaos army. They could be some powerful and mysterious figures that Percy has to interact with. And perhaps some of Percy's old friends might also play a role, either trying to bring him back or having to face him as an enemy now.
The main characters are obviously Percy and Zoe. Percy, who is likely from some sort of heroic or adventure - filled background, and Zoe, who has her own unique identity within the context of this fanfiction, likely related to the chaos realm in some way.
Well, perhaps the plot could involve Percy getting tired of his normal life and being drawn to the chaos realm. There, he meets Zoe and they have some adventures together that make them fall in love. And finally, they decide to get married, facing any challenges that come their way in the chaotic world.