Percy might meet an ancient spirit that has been protecting a particular place for centuries. This spirit could be in the form of an animal and possess great wisdom. Also, he could encounter a group of traveling bards who know a lot about the forgotten lore of the gods. They could help Percy on his journey by providing valuable information. Another interesting character could be a mermaid - like being in the waters near some tropical islands. She might have a unique perspective on the world of the gods.
He could meet other demigods from different regions. For example, a demigod from Scandinavia with powers related to ice.
Percy might meet an old enemy who has somehow been resurrected or changed in the future. This enemy could be more powerful and have a new plan to take over the world or destroy the demigods. Or he could meet a group of time - traveling demigods from an even further future who are trying to fix something in Percy's future that has gone wrong.
Percy might run into Loki. Loki is known for his trickery. He could either befriend Percy for his own devious plans or try to deceive him. Percy, being used to dealing with tricky situations in his own world, would have to be on his guard against Loki's schemes.
He might meet other inter - galactic beings. For example, some sort of space - faring demigods from a far - off galaxy. Or he could encounter powerful entities that are the rulers of other planets.
He could meet his future self. This encounter might be full of surprises as his future self could have different views and experiences. His future self might be more jaded or more powerful.
He could meet other demigods from different pantheons. Since it's a different world, there might be demigods associated with gods that Percy has never heard of before.
In his new life, Percy could meet a kind - hearted librarian. She would be the one to introduce Percy to a whole new world of books that he never had time to explore before. There's also a chance that he'll meet a street - smart kid who helps Percy navigate the more mundane aspects of his new life, like finding the best places to eat or how to fix his bike. And perhaps a new teacher who has a mysterious past and seems to have an inkling of Percy's true nature.
He might meet a new teacher who is secretly a minor god or goddess in disguise.
In this fanfiction, Percy and Thalia could meet a powerful sorcerer who has been exiled from the magical community. The sorcerer could see potential in them and offer to teach them some ancient magic spells that could be useful against their enemies. Additionally, they may come across a group of forest spirits. These spirits could be initially hostile but after learning of Percy and Thalia's noble intentions, they could provide them with shelter and information about hidden paths that lead to safe places away from the threats they are running from.
He might meet some native Alaskan spirits. These spirits could be like the nature spirits he has encountered before but with their own unique Alaskan characteristics.
He could meet some Aboriginal heroes or spirits. They might have their own powers and knowledge that Percy can learn from.