An interesting plot could be that the OC is a being of chaos who has the power to create portals to different realms. Percy and the OC meet when Percy accidentally stumbles into one of these portals. They then embark on a journey through various realms, some of which are completely uncharted by the demigod world. Along the way, they encounter strange creatures and face challenges that test their relationship. Another plot idea is that the OC is tasked by Chaos to teach Percy a new form of combat that is based on chaos energy. This would lead to some really cool training scenes and also a deeper bond between them. And, the OC could have a secret mission from Chaos that involves Percy, and as Percy gradually uncovers this mission, it adds a layer of intrigue to their relationship.
One idea could be that Percy discovers a hidden connection to Chaos while on a quest. Maybe he stumbles upon an ancient artifact that has the power of Chaos within it, and it starts to change him in unexpected ways. For example, he might gain new powers that are related to the primordial chaos, like the ability to manipulate energy in a more chaotic and unpredictable form.
One idea could be that the fem oc is a new camper at Camp Half - Blood with a unique power related to nature. She and Percy have to go on a quest together to save a forest that is being poisoned by a mysterious force. Along the way, they discover that their powers work better together and start to develop feelings for each other.
One idea could be that Percy has unique powers given to him by Chaos. For example, he might be able to control the very fabric of the universe in small ways. Maybe he can manipulate time on a very limited scale, like slowing it down during a fight to gain an advantage.
One idea could be Percy facing a new chaos - themed villain who can manipulate time in a disorderly way. Percy has to find a way to break the time - loops the villain creates.
One idea could be that Percy and Calypso find themselves in a strange new world within the chaos, where the rules of magic are all jumbled. They have to rely on each other's unique abilities to survive. For example, Percy's water - controlling skills and Calypso's nature - based magic might combine in unexpected ways to fend off the chaotic creatures they encounter.
One plot idea could be Percy being sent on a secret mission by the Chaos forces to infiltrate an enemy stronghold. He uses his skills and wits to gather intelligence without being detected.
A possible plot for 'Percy is a Son of Chaos' fanfiction could be Percy being sent on a mission by Chaos itself. This mission could be to restore balance in a part of the universe that has been thrown into chaos (ironically) by some dark force. Along the way, he teams up with some unlikely allies, some of whom are also children of primordial entities. They all have different motives and powers, and Percy has to learn to work with them while also coming to terms with his own identity as a son of Chaos.
One idea could be Percy being chosen as the Chaos Champion and having to face off against an ancient, long - forgotten evil that is emerging from the darkest corners of the Underworld. He'd have to use his new - found powers granted by Chaos in unique ways, like controlling the very essence of water in ways he never thought possible, such as turning it into solid light constructs for defense.
One idea could be Percy having to face a new type of chaos monster that is immune to his usual powers. He would have to find a way to adapt and use his wits more than his strength. Maybe he teams up with an unexpected ally from the realm of chaos.
One idea could be Percy using his skills in a chaotic new world filled with strange mythical creatures that no one has ever seen before. He has to navigate through this chaos and find a way to bring order to this new part of the mythical realm.