One interesting storyline could be Percy and Zoe going on a secret quest together. They might face a new and unknown monster that is a threat to both the camps. Another could be a story where Zoe gets to show Percy some hidden parts of the magical world that he didn't know before.
One interesting storyline could be Percy and Zoe teaming up with Lemon on a quest. Maybe they are searching for a lost artifact that has the power to save the demigod world. They face various monsters along the way and have to use their combined skills, like Percy's water - controlling abilities, Zoe's archery skills, and Lemon's unique talents (which could be something like super - intelligence or the ability to communicate with animals).
Well, there might be a fanfiction where Zoe Nightshade and Percy Jackson are forced to work together to defeat a new and powerful enemy. This enemy could be a dark sorcerer who is threatening to destroy the Camp Half - Blood. In the story, Zoe's knowledge of the ancient world and Percy's water powers could combine in really cool ways. For example, Zoe could lead Percy to a hidden spring that has special powers which Percy can use to enhance his abilities against the sorcerer. There could also be a fanfic that delves into Zoe's past more deeply while Percy is there to listen and learn from her story.
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.
One interesting storyline could be Percy's first encounter with a mythological creature as a kid but in a more humorous way. For example, he mistakes a satyr for a really hairy kid at school and tries to befriend it not knowing what it really is.