In certain fanfictions, Percy's mom could be growing lemons in her garden, and these lemons are not ordinary. They might be a gift from a god or goddess. The lemons could have powers like granting temporary invisibility when consumed. This could play a significant role in the story, for example, when Percy needs to sneak into a dangerous place, his mom gives him a lemon to eat so he can pass unnoticed.
Well, in fanfiction, perhaps Calypso uses lemons in a spell to communicate with Percy when he's far away. Since Percy has a connection with her already, the lemons act as a sort of conduit. And then there could be a whole adventure where Percy has to find ingredients to strengthen this lemon - based communication spell to save Calypso from some danger.
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).
One interesting storyline could be Percy Jackson seeking the guidance of Hestia in a time of great turmoil. Hestia, being the goddess of the hearth, offers him a place of calm and wisdom. And perhaps the lemon could be a magical object, like a lemon tree that has special powers and is protected by Hestia. Percy has to figure out how to use the lemon's power to save his friends or defeat an enemy.
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 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.
One interesting storyline could be Percy facing a new and powerful enemy that is a combination of Greek and some other mythologies' creatures. This enemy might be immune to his usual powers, forcing him to find new ways to fight.
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.
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.
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 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.