Nico di Angelo would also be an interesting character to bring in. His dark past and his connection to the underworld could provide a contrast to the more positive and light - hearted relationship between Percy and Rachel. He might have his own motives that either help or hinder Percy and Rachel's mission.
One idea could be that Rachel discovers a new prophecy that only she can decipher, and she has to team up with Percy to stop a new threat to the demigod world. This would put their relationship to the test as they face dangerous monsters along the way.
One great Percy Jackson Rachel fanfic is 'The Oracle's Choice'. It explores a unique relationship between Percy and Rachel as she becomes more involved in the demigod world. Another good one is 'Rachel's New Path' which delves into how Rachel adjusts to her role as the Oracle and her connection with Percy. And 'Percy and Rachel: An Unexpected Bond' is also worth reading as it shows their friendship evolving in unexpected ways.
Annabeth can also be a well - liked character in these fanfictions. Even though the focus is on Percy and Rachel, Annabeth's intelligence and her past relationship with Percy can create some interesting tensions. In some fanfictions, she might be a bit jealous of Rachel, which can lead to some great character - driven drama.
One possible plotline could be Percy and Rachel having a secret adventure together that deepens their relationship. Maybe they discover a hidden part of the demigod world that only they can explore because of Rachel's special abilities as an Oracle.
Fanfiction.net is a classic place to find Percy Jackson Rachel fanfic. There are thousands of stories there, with different takes on their relationship. AO3 is another excellent option. It not only has a huge number of fanfics but also has a community that is very active in providing feedback and reviews. You can also try Wattpad, although it may have a smaller selection compared to the other two, but still, you might find some hidden gems about Percy and Rachel there.
Nyx in Percy Jackson fanfic often represents the unknown and the primordial forces. She can add depth to the story by bringing in the ancient and powerful elements of Greek mythology. As for the 'lemon', it might be used to create a contrast. Maybe it represents something fresh and new in a world filled with old and powerful deities. It could also be a unique object that has some sort of magical property specific to the fanfic's plot.
A fanfic could explore the relationship between Percy, Calypso and the symbol of the lemon. Maybe the lemon is a rare fruit on Calypso's island and Percy has to go on a quest to find more lemons for a ritual. During this quest, they face various challenges together and their relationship deepens.
In a more detailed fanfic scenario, the lemon could have been cursed by an enemy. When Percy brings it to Calypso's island, it starts to cause strange things to happen. Calypso, with her knowledge of magic, and Percy, with his combat skills, must work together to break the curse. Along the way, their bond grows stronger as they face difficulties, and the lemon becomes a central focus of their journey, not just a physical object but a symbol of their combined efforts against the forces that oppose them.