Obviously, Percy is one of the main characters. He is the central figure as the story is about him knowing he is a demigod. His friends like Annabeth could also be main characters. She is smart and resourceful, and she can help Percy navigate the world of demigods.
Another plot could involve Percy dealing with the reactions of his mortal friends and family. They might be scared or in disbelief when he reveals his true nature. He could struggle to keep his relationships intact while also fulfilling his demigod duties. This would add an emotional depth to the story as he tries to balance two very different worlds.
Obviously, Percy himself is the central character. Annabeth would likely be there too, as she's an important part of Percy's story in the original series. Grover, his satyr friend, could also make an appearance. And of course, there might be appearances from some of the gods or goddesses, like Poseidon since he's Percy's father. Maybe even some new demigod characters created specifically for the fanfiction.
In this fanfiction, a great plotline could be Percy's training to become a powerful demigod. He would start from being a bit clueless about his abilities and gradually grow. There might be a mentor figure who guides him. Along the way, he could get involved in the politics of the demigod world. For example, different camps of demigods might have different views on how to deal with the rising threat of an ancient evil, and Percy has to navigate through all that while still learning about himself as a demigod.
In many fanfictions, Percy is shown as one of the most powerful demigods. His feats in the official Percy Jackson series, such as his role in the Titan War and his numerous battles against powerful monsters, form the basis for this perception. Fanfiction authors build on this by giving him new challenges and even greater powers. For instance, they might have him master additional elements related to water, like being able to freeze the entire ocean or create massive tidal waves with a single thought. This makes him seem extremely powerful compared to other demigods in the fan - created stories.
As a demigod, he might have superhuman strength, speed, and the ability to control water. As a magician, he could have the power to cast spells. For example, he could combine his water - controlling ability with a spell to create ice sculptures with magical properties. He might also be able to teleport short distances using magic, which is different from any demigod power he has.
Yes, in some fanfictions, Percy Jackson can be reimagined as a Roman demigod. Fanfiction allows for creative reinterpretations of existing characters, and this is one such interesting take.
The theme of adventure also runs strong. Percy, as a Mayan demigod, goes on quests. These could be to retrieve powerful Mayan artifacts or to stop an evil force that is threatening the Mayan demigod realm. This is similar to his Greek demigod adventures but with a Mayan twist.
Power struggles are also common. Percy might find himself in the middle of a power struggle between different Norse factions or between the Norse and Greek gods. He has to use his wits and newfound powers to navigate these complex situations. This can lead to some really exciting and tense moments in the fanfiction.