One possible plot could be that Percy Jackson, with his demigod powers, somehow gets transported to the world of Overlord. He might initially be seen as a strange being by the denizens of that world. He could team up with some of the characters from Overlord to fight against a common enemy, like a new powerful dark force that threatens both his world and the Overlord world. His water - based powers would be quite unique there and could be used in creative ways during battles, for example, to put out fires in a burning city or to create barriers against enemy attacks.
Percy would likely be very curious about the characters in the Overlord world. He might approach them with his usual friendly and adventurous attitude. The Overlord characters, depending on their nature, could either be hostile or intrigued. For example, the more powerful and evil - inclined characters might see Percy as a threat and try to eliminate him. But the more neutral or good - hearted ones could be interested in learning about his powers and his world.
One great 'Percy Jackson Overlord' fanfiction is 'The Demigod in Nazarick'. It combines the magic and adventure of Percy's world with the dark and complex setting of Overlord. Another one could be 'Percy and Ainz Ooal Gown's Alliance' which imagines an alliance between Percy and the powerful Ainz. There are also some that focus on how the demigods would react to the different races in the Overlord universe.
The theme of identity is quite prominent. When Percy enters the Overlord world, he has to re - evaluate who he is in this new context. Is he still just a demigod? Or does he become something else? And the theme of discovery is there too. Characters discover new powers, new places, and new ways of thinking as they cross over between the two universes.
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.
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.
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.
I really like 'Percy in the Marvel Universe'. In this fanfiction, Percy gets transported to the Marvel universe. He has to figure out how to get back home while also dealing with all the superheroes and villains there. It shows his character development as he tries to adapt to this new and very different world. The story also has some interesting pair - ups, like Percy and Spider - Man becoming friends and having adventures together.