A third plot idea could be a post - Gaea - defeat fanfic where the world is in chaos because of the damage she caused. Percy and his friends have to not only deal with the physical destruction but also the political unrest among the different mythological factions. They might have to find a way to heal the earth, which was Gaea's domain, and restore balance among the gods, demigods, and mortals.
One plot idea could be Gaea's redemption. In the original series, she was a major villain, but in a fanfic, she could be given a chance at redemption. Maybe Percy and his friends discover that Gaea was being controlled by a more powerful and malevolent force all along, and they have to work with her to defeat this greater evil.
Another interesting plot is a time - travel fanfic where Percy goes back in time to before Gaea fully awakens. He tries to prevent her awakening by changing certain events in the past. This could involve him having to work with some of the older gods and goddesses who were around during Gaea's earlier days.
One idea could be that Percy has a dream where Gaea is trying to corrupt the power of a magical lemon tree. The lemon tree has the ability to heal demigods, but Gaea wants to use it to create chaos. Percy, with his friends, has to protect the tree. Maybe the lemons from the tree can also be used as weapons against Gaea's minions, like when thrown, they release a burst of purifying energy.
One idea could be Percy having to face challenges in a world where Gaea has more direct control over the elements. For example, the earth itself could be constantly shifting and changing, creating new terrains and obstacles for him to overcome. Another could be Percy forming an unlikely alliance with some of Gaea's other children who are also having second thoughts about their mother's destructive plans.
Perhaps the Daughter of Gaea is sent on a mission by Gaea to infiltrate Camp Half - Blood. But instead of causing harm, she falls in love with the sense of community there. She starts to secretly help the campers prepare for Gaea's attacks. She could use her connection to the earth, which is different from the demigods' but still useful, like sensing when Gaea is about to send her minions.
One idea could be Percy having to choose between the powers of Kronos and Gaea. Another could be Percy teaming up with some unexpected allies from the realms of Kronos and Gaea to fight a new common enemy. Maybe Percy discovers a hidden prophecy that involves his lineage as the son of Kronos and Gaea and has to fulfill it to save the world.
Well, a possible plot could be Percy being sent on a quest by Gaea. But instead of following her orders blindly, he uses the quest to gather information about her weaknesses. He could form an unlikely alliance with some minor gods who also oppose Gaea. As for his relationship with his old friends, they would be in shock and some might even try to 'rescue' him from Gaea's influence, leading to some tense and emotional encounters.
One idea could be Percy having strange, prophetic dreams about Gaea that lead him on a quest to understand her true nature before she fully awakens. Maybe he discovers an ancient bond between them that was long forgotten. Another could be Gaea trying to tempt Percy to join her side by offering him power and the ability to reshape the world in a way he might think is better. For example, she could show him a vision of a perfect world without the constant threat of monsters, but with a hidden, dark price.
In a fanfic, perhaps Percy and his friends accidentally stumble upon Medusa's lair while on a quest. But instead of immediately attacking, Medusa offers them a deal. She says she will give them a valuable clue to complete their quest if they help her get revenge on one of the minor gods who wronged her in the past. Percy and his friends then have to decide whether to trust Medusa or not.
Another plot could involve Percy's friends getting accidentally transported to a different realm in the Percy Jackson universe. They have to rely on their friendship and the skills they've learned from Percy to survive and find their way back. For example, they might end up in the Underworld and have to navigate past various challenges without Percy at first.
One idea could be a mortal accidentally stumbling into Camp Half - Blood and having to adapt quickly to the world of demigods. Maybe they have some hidden power that only reveals itself in this new environment.
One idea could be to create a new quest within the game world. For example, Percy and his friends have to retrieve a powerful artifact that was stolen by a new type of monster. This could involve exploring new areas of the game, like a hidden underwater city that has never been discovered before. Another plot could be a tournament in the game where demigods from different cabins compete against each other in various challenges. This would show off their different skills and powers. A third idea is that there's a glitch in the game that's causing real - world problems in the Percy Jackson universe, and they have to figure out how to fix it before it's too late.