Well, one idea for this crossover could be that Savitar somehow ends up in the world of Percy Jackson. Maybe he's chasing after some new kind of speed - the speed of a demigod? And Percy has to figure out how to deal with this strange, super - fast being who doesn't seem to follow the normal rules of the Greek myth world.
One great 'Percy Jackson Crossover Fanfic' is 'Percy Jackson and the Avengers'. It combines the world of Percy Jackson with the Marvel universe in a really interesting way. The characters interact in a believable manner and there are some really cool fight scenes.
Another idea is that Sophie Foster from KotLC travels to the Percy Jackson universe. She could be mistaken for a demigod at first. She would have to learn about the Greek gods and monsters. Her telepathic abilities would be really useful in the Percy Jackson world. For example, she could communicate with some of the monsters to find out their plans. And Percy and his friends would help her understand this new and dangerous world.
Another possibility is that Percy somehow gets transported to Eragon's world. He has to adapt to the new environment and figure out how his demigod powers work there. Eragon could initially be suspicious of Percy but then they realize they can help each other. Percy could teach Eragon about water magic, which is new in Eragon's world, and Eragon could show Percy how to ride a dragon, which would be an amazing experience for Percy.
One way could be to have Percy Jackson's powers of being a demigod interact with the superpowers of the Avengers. For example, his ability to control water could be used in a joint mission with Thor's lightning powers. Maybe they are facing a common enemy that can only be defeated by combining their unique skills.
One idea could be that Naruto, with his powerful chakra and skills, is somehow transported to the world of Percy Jackson. He might be mistaken for a demigod because of his extraordinary abilities. Naruto could then team up with Percy to fight against a common enemy, like an ancient monster that threatens both their worlds.
Another one to check out is 'Justice League meets Camp Half - Blood'. In this fanfic, the Justice League discovers Camp Half - Blood. It's cool to see how Batman would interact with Chiron, or how Wonder Woman would view the demigod powers. There are a lot of great character moments as the two very different universes collide.
One great Percy Jackson crossover fanfiction is the one where he crosses over with the Harry Potter universe. It's exciting to see how the magic of the two worlds interact and how Percy and Harry might team up. Another good one is the crossover with the Avengers. Imagining Percy fighting alongside superheroes like Thor and Captain America is really cool.
One great 'Percy Jackson Supernatural Crossover Fanfic' is 'The Hunters and the Winchesters'. It combines the world of Greek mythology from Percy Jackson with the demon - hunting of Supernatural in a really engaging way. The characters from both universes interact in a believable manner, and the plot keeps you hooked from start to finish.
When writing a 'Percy Jackson Supernatural Crossover Fanfic', it's important to balance the two worlds. Don't let one overshadow the other. You can introduce new characters that are a mix of both universes, like a demigod who was turned into a hunter. Also, research is key. Look into the different mythologies and Supernatural episodes to get inspiration. Build up the story gradually, starting with the initial encounter between the two groups and then leading to a big climax where they have to use their combined skills to save the day.