The exploration of different mythologies is also a theme. Castiel is associated with Christian angel mythology, while Percy is part of Greek mythology. Fanfiction might delve into how these two mythologies interact or clash when the two characters meet. It could be about how they view each other's deities or how the rules of their respective mythologies affect their relationship.
You can try fanfiction platforms like Archive of Our Own (AO3). There are often a wide variety of fanfictions in different categories. Just search for 'Castiel x Percy Jackson' and you'll likely find many interesting stories written by fans from all over the world.
One interesting 'Percy Jackson Castiel' fanfiction could be where Castiel, with his angelic powers, somehow gets involved in the world of Percy Jackson. Maybe he teams up with Percy to fight a common enemy like a powerful ancient monster that threatens both the demigod and angel realms.
A really good 'Percy Jackson x Clarisse Fanfiction' is 'When Percy and Clarisse Train Together'. In this one, they are forced to train together and through the process, they discover new things about each other. They start to respect each other more and it's a great read for those who like character - development - focused stories.
One aspect of 'Percy Jackson x Gaia Fanfiction' could be the unique power dynamics. Percy has his own set of powers from being a demigod, and Gaia is an extremely powerful primordial goddess. Their interaction in fanfiction might explore how Percy, with his courage and skills, contends with Gaia's all - encompassing power. It could also delve into the moral and ethical implications of Percy's relationship with such a powerful and ancient being.
You can try Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, including those that combine different universes like 'Percy Jackson' and 'Castiel' related ones. Just use the search function and type in relevant keywords like 'Percy Jackson Castiel' to find the fanfictions you're interested in.
The theme of sacrifice is also quite common. Sally has already made sacrifices for Percy in the original series, and in fanfiction, this can be exaggerated or explored further. It could be something as simple as sacrificing her own comfort for Percy's well - being, or more extreme sacrifices in the face of greater threats. Additionally, the theme of Percy understanding Sally's sacrifices and how it affects his view of her as a mother and a person is also often explored in these fanfictions.
For Percy, his loyalty and sense of adventure can be emphasized. He could be the one to initiate contact with Elsa, seeing her as a new and exciting mystery. His skills in combat and his ability to think on his feet would come in handy when they face challenges together. For Elsa, her growth from a withdrawn and fearful queen to someone more open and trusting can be shown. Meeting Percy, who is so different from the people in her world, could be a catalyst for this change.
The theme of family also comes up. Percy has a complex family situation, and Hestia can be seen as a mother figure in some fanfictions. This relationship can explore what it means to have a stable and loving family member in the chaotic world of Percy Jackson. It can also show how Percy responds to this new kind of family connection, perhaps growing and maturing as a result of Hestia's influence.
There's also 'Fusion of Foes'. This fanfiction is unique because it combines elements of magic and mystery. Percy and Luke find themselves in a situation where they must use their combined powers to solve a mystery that could destroy their world. The relationship between them is portrayed in a very engaging way, with lots of banter and moments of mutual respect that develop throughout the story.