A plot might revolve around Percy's identity crisis. Even though he has become a god, he still feels like a demigod at heart. He misses his old life and the simplicity of it. He could also have to prove himself worthy of being a god. The other gods might give him tasks to complete. If he fails, he could lose his new - found godhood. And perhaps his journey to becoming a full - fledged god involves traveling to different realms and gaining wisdom from ancient beings there.
One possible plot could be Percy having to deal with new powers. He might struggle to control them at first, like accidentally causing thunderstorms when he's angry. Another plot could involve other characters' reactions. His friends might be in awe or a bit scared. For example, Annabeth could be worried about how this change will affect their relationship. Also, Percy could face new enemies who are jealous of his new god - like status or want to use his powers for their own evil plans.
Well, in such a fanfic, a plot could be Percy being thrust into the world of the gods. He has to learn their ways and politics. Maybe he gets involved in a power struggle among the gods. Since he's new to being a god, some gods might try to manipulate him. On the other hand, he could also use his new status to help the demigods more effectively. He might be able to create a safer haven for them, away from all the monsters that constantly attack them.
One possibility could be that Percy, as a new god, would have to deal with the complex politics of Olympus. He's always been an outsider, and now he'd be thrust into a world of power plays and ancient rivalries. Maybe he'd try to change some of the archaic rules that the gods have held onto for centuries.
Perhaps the fanfic could start with Lemon discovering a prophecy that involves Percy and Khione. They then have to come together to figure out what the prophecy means. Along the way, they face various challenges. Khione's powers might be waning, and Percy has to use his powers to protect her while Lemon tries to find a way to restore her powers. This could lead to a deep bond forming between the three characters as they rely on each other.
It could be an old enemy who now sees Percy as an even greater threat. Maybe Kronos' remnants. Since Percy is now a god, they might fear that he'll be able to fully destroy them. So they try to stop him from getting used to his powers or try to steal his powers.
One possible theme could be identity. Percy has always been a demigod, but now looking like a god, he might question who he really is. Is he still the same Percy? Another theme could be power. With a god - like appearance, he might be perceived as having more power, and this could lead to power struggles within the demigod community.
Perhaps he's seen the downsides of being a god in the Percy Jackson universe. Gods are often restricted by their domains and have a lot of responsibilities. Percy, who has always been a bit of a rebel, might not want to be tied down by such rules. He likes his freedom to make his own choices and help people in his own way, not in the way a god is expected to.
One common plot is Percy's struggle with the moral implications of being a God Slayer. He has to deal with the consequences of taking on such a role. Another plot could be Percy being hunted by other gods or forces because of his new status. Also, there might be a plot where Percy has to team up with unlikely allies to face the chaos that ensues after slaying a god.
Another interesting plot might involve Percy facing off against other gods. As the God of Water, he could be seen as a threat or a potential ally. Some gods might try to undermine him, while others might seek his help. This could lead to political intrigue within the pantheon, which is always exciting in fanfiction.
A possible plot could be that Kratos is somehow transported to Percy's world. Percy initially mistakes Kratos for a new threat but then realizes they could work together. They join forces to stop a dark god from rising who wants to destroy both their worlds.
Poseidon is a likely candidate. Since he is Percy's father in the original series, it would make sense for him to take a more active role in raising Percy. He could teach Percy all about the ocean, its secrets, and how to use his water - related powers more effectively.
One possible reason could be that Percy values his humanity. He has seen the flaws of the gods and doesn't want to be like them. In the original series, he has had many experiences with the gods' self - centeredness. So in fanfiction, he might turn down godhood to stay true to his mortal self.