One interesting storyline could be an SI OC who is a daughter of Athena. She could use her wits and knowledge in unique ways within the Percy Jackson universe. For example, she might be able to solve ancient riddles that help save the camp from a new threat. Another could be an OC who is a demigod with the power to control water in a different way than Percy. She could have to deal with the jealousy of other demigods while also trying to prove her worth.
An SI OC in a female - centered Percy Jackson fanfiction could be a healer demigod. She could have to deal with the aftermath of battles, patching up injured demigods. But she also has a secret power that she discovers over time, like being able to communicate with the spirits of the forest. This would lead to her having to balance her normal healing duties with exploring this new power and how it could be used for good in the fight against the Titans or other enemies.
Well, a great storyline could involve an SI OC who is a transfer student to Camp Half - Blood. She has to adjust to the new life, make friends, and face the challenges of being a demigod all at once. Maybe she has a special connection to the minor gods that the others don't understand. Or perhaps she discovers a long - lost prophecy that she is a part of, and has to convince the other characters to believe her.
Another interesting concept is an SI OC who is from a different time period, like the Middle Ages. They would have to adapt to the modern world of Percy Jackson while also using their archaic knowledge and skills to their advantage. Maybe they know ancient battle tactics that are useful against the Titans or Giants. They could also introduce medieval weaponry and fighting styles to Camp Half - Blood.
To create a believable SI OC in a Percy Jackson fanfiction, start with giving them a clear backstory. For example, if they're a demigod, explain how they discovered their powers and how they got to Camp Half - Blood. Also, give them flaws. Maybe they're too impulsive or overly shy. This makes them more relatable.
One possible storyline could be the OC being a new demigod who catches the attention of both Percy and Artemis. Maybe the OC has a special power that is crucial in a new threat that's emerging in the world of the gods. For example, the OC could have the power to control time briefly, which becomes important when an ancient enemy tries to rewrite history to gain power.
One interesting storyline could be Percy as a baby showing early signs of his demigod powers. Maybe he can control water in his crib, like making the bath water swirl around him in a mini - whirlpool. Another could be the reactions of the gods when they discover this new baby demigod. They might be worried about his potential or already planning how to use him in their future schemes.
There could also be a fanfiction where Percy has to face his inner demons in a more psychological way. Maybe he's haunted by the memories of all the battles he's fought and the friends he's lost. His friends then have to help him through this tough time, and in the process, they learn more about each other's deeper fears and insecurities.
One interesting storyline could be where Percy Jackson somehow ends up in Ariel's underwater world. Maybe he's on a quest that takes him there and he has to team up with Ariel to defeat a common enemy, like a sea monster that is threatening both the underwater kingdom and the surface world that Percy is from.
There could also be a fanfiction where the Hunters take in a new recruit who has a mysterious past. This new character might have powers that are unknown to the world of demigods and the Hunters have to figure out how to train and control these powers. Along the way, they discover that this new recruit is somehow connected to an old prophecy that could change the fate of the demigod world.
One interesting storyline could be a Futa Percy Jackson going on a new quest that involves saving a magical realm from an ancient evil. In this fanfiction, Percy's unique form might give her an edge in combat, like being able to use both male and female - like combat styles.
A really engaging storyline could be them being transported to a different era in the world of Greek mythology. They would have to adapt to the different rules and powers that exist in that time while still relying on their own abilities. This would put their friendship and skills to the test in a whole new and exciting way.
One interesting storyline could be a crossover where Percy Jackson meets the Crusaders in a modern-day setting. Maybe they have to team up to fight a common enemy that is threatening both the world of Greek mythology and the historical context of the Crusaders. Another could be Percy using his powers in a way that the Crusaders initially misunderstand, leading to some conflict before they realize they can work together.