Well, Percy is used to strange things, but the multiverse would still throw him for a loop. In the fanfiction, he could start off being skeptical. After all, he's been through a lot in his own world, and the idea of countless other versions of his reality seems far - fetched at first. But as he delves deeper, he might start to see parallels between his world and the other universes in the multiverse, which could make him more accepting.
Obviously Percy himself is very popular. Since it's a 'Percy Jackson Reacts' scenario, he's at the center of it all. Fans love to write about his reactions.
Another interesting scenario could be Percy reacting to fanfics that change the outcome of major battles in the original series. He might be shocked or proud to see how fans rewrite history, like if a fanfic has him winning a battle in a completely different way than he actually did. This can show different perspectives on his powers and leadership skills.
Percy Jackson has a curious personality. In the context of the multiverse fanfiction, this curiosity will lead him to want to understand how the multiverse works. He'll be asking questions and trying to figure out the rules. His brave and head - strong nature means he won't shy away from any threats or challenges in the multiverse. He'll face them head - on, whether it's a menacing version of a monster from his world or a completely new threat from an unfamiliar universe. His personality traits combined will shape his reactions in the fanfiction in a very dynamic way.
One common theme is alternate universes. Fans like to create scenarios where Percy and his friends exist in an anime - like world with different rules and aesthetics. Another theme is character crossovers, for example, bringing in characters from other popular anime series into the Percy Jackson universe.
You can start by looking on popular fanfiction websites like Archive of Our Own (AO3). There are a large number of Percy Jackson - related fanfictions there. Fanfiction.net is also a great place. Just use the search bar and type in 'Percy Jackson anime' to filter the relevant stories.
One possible anime fanfiction could be a crossover where Percy Jackson enters the world of 'Naruto'. He might be intrigued by the ninja world and the different chakra powers, which are somewhat similar to the magic in his own world. Another could be a fanfiction set in the 'Attack on Titan' universe, where Percy has to use his demigod skills to fight Titans.
One idea could be that Percy and his friends get transported into an anime world like Naruto's. Percy could use his water powers in the deserts of Suna and have epic battles against the sand ninjas. They might also learn new skills from the Naruto characters, like chakra control, and in return, teach them about Greek mythology.
Percy, with his powers over water, could be like a water - based ninja in an anime world. His impulsive nature would also add a lot of action and drama. Annabeth could be the smart strategist, similar to characters like Shikamaru from Naruto. Grover could be the comical sidekick but also have important roles like sensing danger in the anime world.