What are some interesting plot ideas for 'Percy Jackson King of Olympus' fanfiction?

One idea could be Percy having to face a new, unknown monster that is immune to water. He'd have to rely on his other skills and the help of his friends in a completely different way.

One idea could be Percy discovers a new, hidden power within himself that is linked to an ancient prophecy. Maybe he can control the elements in a way no demigod has before.

A more complex plot could be Percy getting sent to an alternate dimension where the rules of Olympus are completely different. He has to navigate this new world, make new friends and enemies, and find a way to get back to his own dimension to stop a looming disaster that is about to befall Olympus in his absence.

One idea could be exploring the relationships between the demigods in more depth. For example, how Percy and Annabeth's relationship evolves after the events of 'Blood of Olympus'. Another could be creating a new adventure for the demigods that involves a forgotten prophecy. Maybe they have to travel to a new, unknown part of the mythological world to fulfill it.

One idea could be Percy discovers a long - forgotten prophecy that predicts a major betrayal within Olympus and he has to navigate through the politics and power struggles to expose the traitor. Another could be Percy teams up with some of the minor gods who feel neglected by the Olympians to take revenge in a more peaceful, but still impactful way, like through protests or revealing the Olympians' misdeeds to the mortal world.

One idea could be Percy having to face a new and powerful monster that is immune to water. This would really challenge his typical combat strategies. Another could be Percy getting lost in a forgotten part of the Underworld and having to find his way out while dealing with various underworldly spirits.

Well, you could write a fanfiction where a minor character from the original 'Percy Jackson and the Blood of Olympus' gets their own story arc. Maybe a character who was always in the background but had a lot of potential. For instance, a demigod who discovers a new power related to the blood of Olympus that was previously unknown. They could then go on a journey to master this power and in the process, uncover secrets about the Olympians that were long forgotten.

A cool plot could be Percy getting lost in a different dimension that is related to the Greek mythology but has been forgotten. In this dimension, he has to find his way back while also helping the lost souls there. He could learn new powers and make new allies that would be useful when he returns to his own world.

A really interesting plot could be Percy losing his memories due to a curse. His friends would have to help him regain his identity while also protecting him from enemies who see this as an opportunity to take him out. As he slowly remembers bits and pieces, he uncovers a conspiracy within the Olympian ranks.

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.