The development could involve the Host of Nekhbet teaching Percy about Egyptian magic. Percy, in turn, could share his knowledge of Greek demigod powers. Their relationship could grow from mutual curiosity to a strong friendship or alliance. As they face challenges together, like a powerful monster that is immune to normal attacks, they'd have to combine their skills. The Host of Nekhbet might use their magic to weaken the monster's defenses while Percy delivers the final blow. This would not only progress the story but also show how their two mythologies can interact in a fanfic.
One idea could be a story where Percy Jackson discovers an ancient artifact related to the Host of Nekhbet and has to protect it from evil forces. Maybe it gives him some new powers or knowledge about Egyptian mythology.
In developing Percy, consider his identity. He is half - god, half - human. In the fanfic, he could struggle more with this identity and Sally could play a role in helping him accept it. Sally can be developed by highlighting her creativity. She could come up with unique solutions to problems they face. Regarding their relationship, develop it by adding conflict. Maybe Percy wants to do something dangerous and Sally is against it. Resolving this conflict can lead to a deeper understanding between them and thus develop their characters further.
For Percy, you could show his struggle with the sins in a way that challenges his usual heroic self. For example, if he faces wrath, you can develop his character by showing how he tries to control his anger in a more difficult situation than he's used to. With other characters like Annabeth, she could be tempted by pride in her intelligence and you can develop her by showing how she either succumbs to it briefly and learns from it or resists it and grows stronger in her self - awareness.
You could also develop his character by showing his interactions with other gods and goddesses. As the son of Hecate, he might attract the attention of some deities who either want to help or hinder him. His reactions to their offers and threats would shape his character. For example, if a god offers him more power but at a great cost, how does Percy respond? Does he accept the power out of desperation or does he hold true to his values? This would show his growth and development.
Their relationship can start with mutual dislike and grudging respect. For example, they could be forced to work on a project for Camp Half - Blood. As they work together, they begin to see the good in each other. Percy might notice Clarisse's loyalty to her friends, and Clarisse could see Percy's courage in the face of danger.
Their relationship could start with Percy seeking refuge at one of Hestia's hearths during a difficult time. Hestia, being the gentle goddess she is, offers him comfort and wisdom. This initial encounter could be the foundation for a deeper bond as Percy starts to see Hestia as a motherly figure, much like how he saw Sally Jackson.
Another way to develop their relationship is through moments of vulnerability. If Zoe gets injured during a battle, Percy could take care of her. This would show a different side of Percy to Zoe. Similarly, if Percy is having doubts about his role as a hero, Zoe could offer him advice and support. These exchanges would make their relationship more complex and interesting in the fanfiction.
Percy could start to form new relationships within the Faunus community. These relationships could teach him different values and ways of life. Maybe he'd meet a Faunus mentor who would help him understand and control his new Faunus powers, if he has them. This would be a big part of his development, as he'd be learning from a completely different perspective than he's used to at Camp Half - Blood.
For Percy, his loyalty and sense of adventure can be emphasized. He could be the one to initiate contact with Elsa, seeing her as a new and exciting mystery. His skills in combat and his ability to think on his feet would come in handy when they face challenges together. For Elsa, her growth from a withdrawn and fearful queen to someone more open and trusting can be shown. Meeting Percy, who is so different from the people in her world, could be a catalyst for this change.
Developing his powers further is also a way. Since he's the son of Nyx, he could learn to manipulate different aspects of darkness like creating illusions using shadows or traveling through the dark realms faster. This would not only make him more powerful but also show his growth as a character as he masters these new abilities.