In a fanfiction where Percy Jackson is in another world, there are so many possibilities. He could be seen as a threat by the inhabitants of this new world because of his strange powers. On the other hand, he might be seen as a savior. The new world could have its own set of prophecies and quests, and Percy could get caught up in them. He would have to adapt quickly to survive, using his wits and his combat skills that he developed in his own world.
Well, he might find that his demigod powers work differently. Maybe in this new world, the water doesn't respond to him in the same way as in his own world. He could also encounter new and strange creatures that he has never seen before, and have to figure out how to deal with them without the help of his usual friends from Camp Half - Blood.
If Percy Jackson were in another world in a fanfiction, he could potentially be a complete stranger. The gods and goddesses he knew might not exist there, or they could be very different. He might have to start from scratch, learning about the new world's magic system. He could also meet versions of his friends that are radically different, which would be both confusing and exciting.
He might encounter new and strange creatures. In many fanfictions, Percy could meet unique magical beings that don't exist in his own world. For example, he could come across sentient plants that can communicate or floating islands with their own mini - ecosystems.
In a 'Percy Jackson banished to another world' fanfiction, Percy would be in for a wild ride. He could find that the laws of physics and nature are completely different. For instance, gravity might work in a strange way or time could pass at a different rate. His skills as a fighter and strategist would be crucial. He may have to learn new languages to communicate with the inhabitants of this new world. And he'd probably have to face his own inner demons while being away from his loved ones and the familiar places of his home world.
In the 'Percy Jackson Disappears' fanfiction, perhaps Percy could be kidnapped by an unknown enemy. Maybe it's a new villain who has a vendetta against the demigods. This would lead to his friends, like Annabeth, going on a desperate search for him, facing many dangerous challenges along the way.
In fanfiction, Percy could be in the hospital because he was captured by an enemy and tortured. Now he's there being healed by the camp's healers or some advanced demigod medical technology. Another possibility is that he's having some sort of identity crisis related to his demigod status and it's causing him physical and mental stress, so he's in the hospital for both medical and psychological help.
Well, in this fanfiction, Percy's immortality could lead to some really interesting character development. He may start to feel lonely as he realizes that he will outlive all of his friends. This could cause him to be more withdrawn at first. But then, as he interacts with the students at Westover Hall, he might find new meaning in his immortality. He could start to see it as a way to protect others not just for a short time, but for as long as he exists. He could also form deep and lasting friendships with those who accept him for who he is, regardless of his immortality.
In the fanfiction, Percy might face new challenges related to his demigod status. Maybe he has to deal with the aftermath of the war, like rebuilding Camp Half - Blood or helping new demigods adjust.
Another possibility is a group of outlaws or rebels in the banished world who don't trust Percy because he's from another place. They might think he's been sent to spy on them or take over. So they would constantly try to get rid of him. They could be very resourceful and know the ins and outs of the new world better than Percy, which would make them tough opponents.
Well, he could end up in a situation where all his friends are incapacitated. For example, they are put under a powerful spell. Percy then has to be the lone warrior to fight against a group of evil demigods who are trying to take over Camp Half - Blood. He'd have to use his water - related powers in new and creative ways.
He might go on a solo adventure to discover more about his powers. He could encounter new mythical creatures that he hadn't seen around the camp. Maybe he'll meet some other demigods who are on the run or have their own secret quests.
Well, in this fanfiction, Percy controlling the Styx could lead to some really interesting plot developments. Since the Styx has such a significant role in Greek mythology, it could attract all kinds of mythical creatures and gods. Percy could find himself in the middle of a power struggle as different factions either try to use him or stop him. He might also use the Styx to travel to different realms or access hidden knowledge. And perhaps he would have to face the consequences of messing with such a powerful and sacred entity, like facing the wrath of Hades or other underworld deities.