Percy is a brave and loyal character. His loyalty would mesh well with the flock's sense of unity. He's also quite adaptable, which would help him get used to the flock's way of life. His sense of humor might lighten the mood among the flock members.
Percy has a very adventurous and sometimes rebellious personality. This could be both a good and a bad thing in the context of Artemis' group. On one hand, his willingness to take risks could lead to great victories. On the other hand, Artemis values discipline and he might have to adjust to her rules.
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's water - controlling abilities would be unique in Asgard. He could use it for defense and offense. For example, he could create water shields or water whips to fight against enemies. His ability to breathe underwater might not be as useful in Asgard directly, but it could come in handy if there are any underwater areas or if he has to deal with water - based magic there.
Percy would probably use his powers over water to his advantage. Maybe there are large lakes or rivers in the Jurassic times and he can control the water to create barriers or distractions against the dinosaurs.
Percy Jackson would probably stand out in Forks. He has this whole demigod aura and his powers are quite flashy compared to the more low - key vampires and werewolves. But he might adapt by using his wits. He could blend in by pretending to be a normal human, but his constant awareness of possible threats (which in Forks are vampires and werewolves instead of Greek monsters) would make him seem a bit paranoid to the locals.
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.
Percy's powers would be a great addition to the Avengers in a fanfiction. His control over water could create a lot of strategic opportunities. He could flood an area to slow down enemies or create ice platforms for the Avengers to stand on during battles. Compared to Captain America's leadership and combat skills, Percy could offer a different kind of support. And when it comes to Thor, while Thor controls lightning, Percy could use water to conduct that lightning in different ways for more powerful attacks.
She might bring in her demigod skills. For instance, her knowledge of ancient languages could help the Avengers decipher some mysterious inscriptions they find. Also, her agility and combat training from the demigod side could make her a formidable fighter in the Avengers' battles.
He could be a wildcard. His lack of emotion would make his actions hard to predict. He might join a quest just because it seems logical, not because of any emotional attachment to the cause. For instance, if there's a quest to retrieve a powerful artifact, he'd analyze the risks and rewards and decide based on that, not on things like pride or loyalty like the demigods.
Ice powers could fit in by being a new type of power that challenges the existing power dynamics. For instance, in battles, they could change the terrain by creating ice ramps or freezing lakes for strategic advantages.