In Percy Jackson fanfiction, Goku could be a mysterious outsider who comes to help during a great war against the Titans or some other major threat. His Saiyan fighting spirit and his various energy attacks, like the Kamehameha, could be seen as a new form of magic in that world. He might not understand all the Greek mythology stuff at first, but his pure heart and desire to do good would make him a valuable ally. For example, he could team up with Percy to fight off a horde of monsters. His super speed and strength would give them an edge in battles.
Well, it could be a really interesting and terrifying addition. Maybe it could be some kind of ancient monster that was locked away long ago in the world of Percy Jackson. It could be released by some dark magic or an evil demigod. The xenomorph's ability to adapt and its deadly nature would make it a formidable foe for Percy and his friends.
Percy could fit in as a strategist. His experience in dealing with various gods and monsters gives him a unique perspective on handling threats. He might suggest different approaches that the Avengers haven't thought of before, like using the environment in a more creative way, similar to how he uses water in his battles as a demigod.
Well, Goku's super strength and his ability to constantly power up could be a huge asset in the My Hero Academia fanfiction world. He could be like an otherworldly hero with his Saiyan powers. His Kamehameha wave would be an extremely powerful quirk - like ability. Maybe he could be a visiting hero from another dimension, coming to help out in the battles against the villains in the My Hero Academia universe.
He could be a mentor figure. Given his immortality and vast combat experience from the Naruto world, he could teach the demigods new ways to fight and strategize.
Gosling could be a time - traveling character. He could travel from the real world into the Harry Potter universe and then find a way to enter the Percy Jackson world. His knowledge from the modern world could help him solve problems in both magical realms.
Goku Black could potentially enter the High School DxD world through a dimensional rift or some sort of magical accident. Once there, his Saiyan pride and his dark motives (from his own story) could lead to him either trying to take over the various factions in the DxD world or simply looking for a worthy opponent. He might interact with the main characters like Issei, perhaps seeing him as a target to prove his superiority or a potential ally in his own schemes.
Naruto's chakra control could be seen as a form of magic in the Percy Jackson world. His ability to use jutsu like the Fireball Jutsu could be like a new type of spell. And his summoning jutsu might call upon some unique creatures that don't exist in the Percy Jackson universe.
In Percy Jackson fanfiction, the seven deadly sins can be incorporated as powerful forces or entities. For example, they could be ancient evils that the demigods have to combat. This adds a new layer of danger and conflict to the already complex world of Percy Jackson.
In a fanfiction, the Percy Jackson characters could fit into the Pokemon world in several ways. For example, they could be travelers from another dimension (the demigod world) who are trying to understand the rules and ways of the Pokemon world. Percy could form a special bond with water - type Pokemon, similar to how he has a connection with water in his own world. Annabeth could be intrigued by the architecture and layout of the Pokemon cities and use her knowledge to help the group navigate. Grover might get along well with Grass - type Pokemon as he has an affinity for nature. And they could all participate in Pokemon contests or battles, using their demigod skills to enhance their performance.
If we consider how the Percy Jackson characters would fit into LOTR's world, we also have to think about the different races in Middle - earth. The demigods might have different relationships with the hobbits, dwarves, elves, and men. The hobbits could be both curious and a bit scared of the demigods at first. The dwarves might be interested in the demigods' weapons and their fighting abilities. The elves, with their own magic and long - lives, could compare and contrast their existence with that of the demigods. And the men of Middle - earth would likely be both cautious and eager to use the demigods' powers for their own purposes in the fight against Sauron.