Another plot could involve Percy being transported to the Egyptian afterlife by mistake. There, he has to navigate the complex rules and gods of the Egyptian underworld while trying to find a way back home. He might encounter Egyptian gods who mistake him for a Greek invader and he has to prove his good intentions.
One idea could be Percy having to team up with an Egyptian demigod to stop a common enemy that is causing chaos in both Greek and Egyptian mythological realms. Maybe a powerful monster that is using the powers of both mythologies to grow stronger.
One idea could be a story where Percy has to team up with a minor Greek god, like Hypnos, to defeat a new threat that's causing nightmares across the demigod world. Another could be a fanfic exploring what would happen if Percy was sent back in time to the age of the original Greek heroes and had to prove himself among them.
Well, a great plot could involve Percy being transported to the Norse realm and having to prove himself to Odin. He might have to participate in a series of trials that are designed for Norse heroes. Or perhaps he gets caught in a feud between different Norse factions and has to use his wits and powers to bring peace. He could also discover a connection between the Greek and Norse pantheons that no one knew about before.
One idea could be Percy having to face a new, powerful enemy that is a threat to his newfound position as king of the gods. This enemy could be a primordial being that has been awakened. Another plot could involve Percy trying to reform the rules among the gods, which causes a lot of internal conflict as the other gods resist change. And perhaps Percy discovers a long - lost prophecy related to his kingship that changes everything he thought he knew.
A possible plot for this fanfiction is that the curse makes Percy lose his memory bit by bit. He forgets his friends, his past adventures, and even his own identity. As he struggles to figure out what's wrong with him, he starts having strange visions that are both a clue to the curse and a danger in themselves. Maybe the gods who cursed him are trying to erase him from existence, and he has to rely on his instincts and the few remaining memories to fight back. He might meet new characters who are either trying to help him or are part of the gods' plan to keep him cursed.
A possible plot could be that Percy is summoned to Japan by the Shinto gods to help stop an ancient evil that is threatening both the Greek and Shinto worlds. This evil could be a powerful demon that has the ability to disrupt the balance between the two pantheons.
One idea could be exploring a new prophecy that involves Percy and his friends having to team up with some of the lesser - known gods. This would introduce new characters and powers into the story.
Perhaps Percy is framed for a crime against the gods and has to fight them while also trying to prove his innocence. He could travel to different realms in the process, seeking evidence and allies. Along the way, he might learn some dark secrets about the gods that could change his perspective on them forever.
A really interesting plot would be if Percy lost his memory and ended up in a mortal town. He has to figure out who he is on his own while still being hunted by some old enemies. The gods are aware of his situation but can't interfere directly because of some ancient rule. So Percy has to rely on his instincts and any small clues he can find about his past to get back to his normal self and his life at Camp Half - Blood.
Perhaps a fanfiction where the New Gods create a sort of competition for demigods. Percy enters this competition and discovers that there are rules he's not used to, and he has to use his wits and skills in new ways to win. And along the way, he makes some unexpected allies among the new gods.
One idea could be a story where a new demigod discovers they have the power to communicate with the long - forgotten minor gods and goddesses. This new ability throws the established order at Camp Half - Blood into chaos as they try to figure out if this is a good or bad thing.