Well, a really cool plot for a Percy Jackson - One Piece crossover fanfiction might involve the search for a powerful and mythical treasure in the One Piece world that has a connection to the Greek gods. The Straw Hat Pirates and Percy's gang could be on a race against some evil force, like a powerful sea devil or a dark sorcerer, who also wants the treasure. Percy could have some knowledge about the treasure's origin from his Greek mythology background, which would be super helpful.
Perhaps Percy is on a quest related to Poseidon and accidentally crosses paths with Aquaman. They initially have a misunderstanding, thinking the other is a threat. But then they realize they both have a common goal - to protect the seas. So they team up to stop a group of evil sea witches who are polluting the ocean and causing chaos among the sea life. Aquaman uses his trident and connection to the ocean's life, while Percy uses his sword and his wits to outsmart the witches.
One possible plot could be that the characters from Glitchtale end up in the world of Percy Jackson. Maybe Betty, from Glitchtale, could be mistaken for a new type of monster by the demigods. The demigods then have to figure out whether she's a threat or not. And at the same time, the Glitchtale characters are trying to find a way back to their own world.
Well, it could be about the Straw Hats accidentally ending up in the Marvel universe. They meet the Avengers and at first there's some misunderstanding because of their different ways. But then they realize they can work together. Maybe Luffy is fascinated by Thor's hammer and tries to lift it, while Zoro wants to have a sword fight with Captain America's shield.
Percy would probably be really curious about Luffy's devil fruit powers. He might try to figure out if there's any connection to the magic he knows. Luffy, on the other hand, would be excited to have Percy on board and would want to see his water powers in action.
One possible plot could be that the Volturi from Twilight discover the existence of demigods from the Percy Jackson world. They see the demigods as a threat to their vampire supremacy. Percy and his friends have to team up with some of the more friendly vampires, like the Cullens, to fend off the Volturi. This would bring together the magic and powers of both universes in an epic battle.
In a 'naruto garra percy jackson crossover fanfiction', it could start with Percy Jackson being sent to the Naruto universe by some strange magic. There, he meets Naruto and Garra. They soon realize that there are dark forces at work in both their worlds that are connected. They embark on a journey to find the source of this evil. Along the way, Naruto shows Percy his village and the way of the ninja. Garra shares his past and how he overcame his inner demons. Percy, in turn, teaches them about Greek mythology and the powers of the demigods. As they get closer to the source of the evil, they must combine their unique skills and knowledge to defeat it.
Well, perhaps there's a villain in the Percy Jackson universe who discovers that the iCarly web show has a huge following and decides to use it as a way to spread chaos. The demigods have to team up with the iCarly crew to stop this. The iCarly gang has to learn about the world of Greek mythology really fast and help the demigods navigate the modern world of technology and media to defeat the villain.
Well, it could start with a magical accident. In the Percy Jackson universe, a spell gone wrong sends Percy, Annabeth, and Grover into the land of Alagaësia from Eragon. There, they discover that the demigod powers Percy has are seen as a strange and new form of magic. Eragon is initially suspicious of them but realizes they can help in his fight against Galbatorix. They combine their skills, Percy's water - controlling powers and sword - fighting skills, along with Annabeth's strategic mind and Grover's nature - sensing abilities, with Eragon's dragon - riding and magic - wielding skills to take on the dark forces.
The plot could involve a powerful magical artifact that has military applications. The NCIS comes across this artifact during an investigation but doesn't understand its true nature. Percy Jackson and his friends, who are on a quest to retrieve the artifact for the demigod world, cross paths with the NCIS. There is a lot of miscommunication at first as the two groups have different goals and ways of operating. But as they realize that they are both facing a common threat from a group of rogue demigods and power - hungry military personnel, they join forces. Percy uses his knowledge of the demigod world and his powers to help the NCIS agents navigate the magical aspects while the agents use their resources and combat training to take on the human threats.
One possible plot could be that the Greek gods, noticing the powerful threats the Avengers face, send Percy Jackson and his friends to help. Percy could use his water powers to assist in putting out fires during a battle like the one in New York. Meanwhile, Thor could be intrigued by Percy's connection to Poseidon and they could exchange stories about their godly fathers.