Power and its corrupting influence could be another theme. With the powers that come from Hades and Persephone, Percy could be tempted to use them for the wrong reasons. For example, the power over the dead could be misused, and he has to learn to use his powers responsibly.
A major theme could be identity. Percy has to come to terms with being the son of two very powerful and different deities. It's not like being the son of Poseidon where he has a more straightforward heroic image. Here, he has to figure out who he really is.
One way to develop the storyline could be to explore Percy's struggle with his new identity. Since Hades and Persephone are such complex deities, Percy might have a darker side to him. He could struggle with controlling powers related to the Underworld, like shadow manipulation or communicating with the dead. For example, in a school setting, he might accidentally let out some spooky manifestations when he's stressed.
Annabeth Chase might also be an ally. Her intelligence and strategic thinking could be valuable assets for the son of Hades. She could help him plan his moves, especially when dealing with the complex politics among the demigods and gods.
Well, one way to re - imagine their relationship is to make it more of a partnership. In the original myths, Persephone is often seen as a victim of Hades' abduction. But in fanfiction, we could see them as two powerful deities who came together by choice. They could be equal partners in ruling the Underworld, with Hades respecting Persephone's opinions and decisions more.
Well, there could be new demigod children of Hades. Maybe a girl who has the power to control the shadows in a unique way, like she can use them to create portals to different parts of the underworld. Or a boy who can communicate with the dead in a more advanced way than the usual children of Hades, and he has some sort of prophecy related to Percy.
One idea could be Percy discovering his unique heritage as the son of Hades and Persephone and struggling to fit in among the other demigods. He might have powers related to the Underworld that set him apart, like the ability to control certain types of plants that grow in the Underworld. Another plot could involve him having to deal with the politics between the gods because of his parentage. For example, Zeus might be suspicious of him due to his connection to Hades.
Another theme is the duality of the underworld and the overworld. Fanfics often play with the idea of Persephone being a bridge between these two realms, and how her relationship with Hades affects both the light and dark aspects of the world.
Love is a very common theme. Their relationship, which is a complex mix of passion and power, is often explored in depth.
There might be a fanfiction where Persephone uses her powers to help Percy Jackson understand some of the deeper mysteries of the Greek world in the context of the Percy Jackson universe. This could involve her connection to Hades and how that affects the balance of power. For example, she could show Percy how to navigate certain dark areas that are related to Hades' domain.
One potential plot twist could be that the gods try to keep his true parentage a secret, but Percy discovers it through a series of strange dreams or visions. Another could be that he has a power that is completely unexpected, like the ability to combine the powers of the moon (from Artemis) and the sea (from Poseidon) in a way that no one has ever seen before. For example, he could create tidal waves that are influenced by the phases of the moon.
One common theme is the struggle with identity. Since Percy's parentage is so different from the original, he has to figure out who he really is. Another theme is power. With Hades and Artemis as his parents, he could have a whole new set of powers to discover and control. And there's also the theme of acceptance, both from himself and from the other characters in the Percy Jackson universe.