Well, it could have a plot where Percy discovers his connection to Kaguya through some ancient prophecy. Maybe there are special powers he gains from this heritage that he has to learn to control while still dealing with his regular demigod stuff like fighting monsters and going on quests.
In a Percy Jackson becomes a goddess fanfiction, the story could start with some sort of magical accident or a powerful spell that turns him into a goddess. As a goddess, Percy would have to adapt to a whole new way of life. He'd no longer be just a hero on quests but a divine being with a different set of rules. His powers would likely be enhanced, and he might gain abilities like shape - shifting or more powerful control over water. His journey would involve not only coming to terms with his new identity but also using his new powers to protect the world in a different way than he did as a demigod.
Well, it could involve Percy having some sort of special connection with the Fates. Maybe he can influence destiny in ways others can't. For example, he might be able to change the fates of his friends in dangerous situations, like when they're facing a powerful monster. This would make for an interesting dynamic as he'd have to balance the power he has with the natural order of things.
It could involve Percy facing new challenges related to the concept of balance. Maybe he has to deal with a Titan who is disrupting the natural order. For example, the Titan might be causing chaos between the mortal and the demigod worlds, and Percy has to find a way to stop it.
One possibility is that Percy's new status as the adopted son of Ouranos gives him unique powers. He might be able to control primordial elements like the very essence of the sky and space. For example, he could create storms on a much larger scale than before, drawing power from the origin of the heavens. Another aspect could be his relationship with the other gods. They might view him with a new level of respect or fear, which would change the power dynamics in the demigod world. And Percy would also have to deal with the expectations and responsibilities that come with being related to such a powerful primordial being.
If Percy is a descendant of Kaguya, his powers might change in a way that combines his demigod abilities with some unique Japanese - inspired powers. For example, he could gain the power of illusions, like Kaguya was said to have in some stories. This would be a new and unexpected addition to his combat and survival skills. He could use these illusions to deceive enemies or find hidden paths. Also, his speed and agility might increase, as Kaguya was often depicted as a very graceful and swift figure.
Well, it could involve Percy going on a quest in Mars' domain. Maybe he has to retrieve some powerful weapon that was lost there. It could also include him facing off against Mars' enemies or creatures specific to that realm.
In this fanfic, Percy's identity could be in flux. Being adopted by Aphrodite, he may start to question his own self - worth outside of his heroic deeds. His new 'family' might introduce him to a more hedonistic lifestyle. He could be dragged into Aphrodite's schemes to make the world more 'beautiful' in her eyes, which could lead to him having to face off against other gods or monsters who oppose her ideas. His journey would likely be full of self - discovery as he figures out how to be Percy Jackson while also being part of Aphrodite's world.
In this fanfiction scenario, Percy's relationship with other characters would change. His friends might be a bit more wary of his new - found charm powers. And he could have a whole new set of enemies among Aphrodite's rivals. Also, his love life would be even more complicated. With Aphrodite as his mother, there would be all kinds of expectations and potential love - related plots.
It could involve Percy having new and powerful abilities. Since Ouranos is a primordial god, Percy might have control over fundamental elements like the sky or the very essence of creation. For example, he could be able to manipulate the air in ways he couldn't before, like creating powerful storms or even pockets of different atmospheres.
In this fanfiction, Percy's character arc could be about him coming to terms with his new identity as the son of Horus. He would need to learn about Egyptian culture and mythology. His journey could take him to different places in the Egyptian mythological realm. He might discover new forms of magic or powers that are unique to this new heritage. His friends would also have to adjust to this new Percy, and there could be a lot of drama and adventure as a result.