A possible storyline could be a competition between the Greek and Egyptian demigods, organized by the gods of both pantheons. Percy represents the Greeks while a powerful Egyptian demigod represents the Egyptians. They have to complete a series of tasks that involve both Greek and Egyptian mythology elements, like retrieving a powerful artifact that has been hidden in a place protected by both Greek and Egyptian magic.
Another storyline might involve Percy getting lost in the Egyptian afterlife. He has to navigate through the different realms with the help of Egyptian gods such as Thoth, who is known for his wisdom. Along the way, he discovers secrets about the connection between the Greek and Egyptian pantheons. This could include how their powers are related and how the two mythologies might have influenced each other in ancient times.
One idea could be Percy having to team up with an Egyptian demigod to stop a common enemy that is causing chaos in both Greek and Egyptian mythological realms. Maybe a powerful monster that is using the powers of both mythologies to grow stronger.
Percy would interact in a cautious yet curious way. He'd be curious about their powers, like Anubis' role in the afterlife. But he'd also be cautious as he doesn't know how they'll react to a Greek demigod. He might use his charm, which has worked on some Greek gods, to try and build relationships. However, he may face some resistance from the more xenophobic Egyptian gods who see him as an intruder.
In a fanfiction where Percy Jackson meets the Egyptian gods, it would be a clash of two mythologies. Percy's sword skills and ability to control water might not be as useful as he thinks against the Egyptian gods' unique powers. He could befriend some of the Egyptian gods who share similar values to the Greek gods he knows. However, he might also make enemies among those who see him as an outsider. The fanfic could explore how Percy uses his wits and his knowledge of Greek mythology to navigate the world of Egyptian gods and their associated creatures.
One interesting storyline could be about a new demigod arriving at Camp Half - Blood and having to prove themselves. They might face challenges that the original characters in the Percy Jackson series didn't, like dealing with a new type of monster that is specifically targeting new recruits. Another could be a fanfiction where the gods interact more directly with the campers in ways that are not in the original books. For example, Zeus coming down to give a special training session to the lightning - wielding demigods.
Percy would probably be initially cautious when interacting with Egyptian gods. For example, when meeting Ra, the sun god, Percy might be in awe but also a bit hesitant as their powers are so different. He would need to show respect as he does with the Greek gods. The Egyptian gods, in turn, might be curious about Percy's abilities, especially his control over water which is not as prominent in Egyptian mythology.
Set, the Egyptian god of chaos. He could be a great antagonist as he might see the combination of Greek and Egyptian powers in Percy and the other demigods as a threat to his own plans of spreading chaos. He could try to manipulate events to turn the two groups against each other.
Another storyline could involve her relationship with Percy Jackson. Maybe she has a bit of a rivalry at first because she's from Athena and he has his own heroic status. But then they end up having to team up against a common enemy, like a new powerful monster that neither could defeat alone. During this, they learn to respect each other's strengths.
A cool storyline could be that there's a memory - stealing monster in Camp Half - Blood. Percy is the first victim, and as he forgets who he is, he starts to act differently. His friends notice the change and realize something is wrong. They then search for a way to defeat the monster and restore Percy's memories. Along the way, they might have to face challenges like Percy unknowingly helping the monster or getting into dangerous situations because he doesn't remember his skills.
One popular storyline could be Percy and Annabeth going on new adventures together, exploring different parts of the mythological world that weren't covered in the books. For example, they could travel to a long - forgotten island full of ancient and powerful magic.
A great story idea could be Percy using his Egyptian descent to bridge the gap between the Greek and Egyptian pantheons. He could introduce Greek concepts to the Egyptian gods and vice versa. For example, he might teach the Egyptian demigods about Greek battle strategies while learning about Egyptian divination methods from them. This could lead to an alliance between the two groups in the face of a common threat, and Percy would be at the center of it all, struggling to balance his two heritages.