It could involve Percy dealing with the guilt of being the sole survivor. Maybe he has to face the families of the fallen comrades and explain what happened. He might also be on a journey to find out if there was a deeper reason for him being the only one left alive.
Perhaps in this fanfic, Percy is the only survivor but he's not entirely alone. He might be haunted by the spirits of his fallen comrades who give him guidance and strength. He could use this to fight against the remnants of the evil forces that still lurk in the shadows, all while trying to rebuild the world that was shattered in the final battle.
Percy would likely become more withdrawn at first. The trauma of being the sole survivor would take a toll on his usually outgoing and confident personality. He might start to question his own abilities and whether he could have done more to save his friends.
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.
A possible plot could be that the female sole survivor is on a mission to find a cure for a disease that is ravaging her community. She crosses paths with John Hancock, who has his own reasons for being involved in the situation. They initially clash due to their different approaches but eventually team up.
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.
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.
It could entail Percy being in a strange place, like a new realm in the demigod world. His loneliness would be palpable as he tries to figure out how to get back. His power, say his water - controlling abilities, might be fluctuating in this new environment, making him feel even more lost. He might start to doubt himself and his place among the demigods.
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.