A great plot could be Percy getting caught in a power struggle between Athena and Poseidon's followers. Since he is the son of both, he is a symbol of unity or a threat, depending on how different groups view him. He could be forced to prove his loyalty to both sides while also trying to maintain peace among them. This could involve battles, political intrigue, and lots of character development as he tries to figure out where he truly belongs in this complex world of gods and their followers.
Perhaps Percy discovers a hidden prophecy that foretells his role in a major event involving Athena and Poseidon. This prophecy could be misinterpreted by some, leading to Percy being hunted or having to go on the run. Along the way, he meets new allies and enemies, all while trying to understand the true meaning of the prophecy and his place in the grand scheme of things. He might have to use his wits and powers in unexpected ways to survive and fulfill his destiny.
One idea could be Percy going on a quest to find a lost artifact of Athena that has the power to restore balance in the world of the gods. Another could be Percy having to face off against a powerful enemy who is specifically targeting him because of his relation to Athena. Maybe he discovers some long - lost siblings also sired by Athena during his adventures.
Another plot could involve Percy discovering a hidden connection between Poseidon and Athena that was long forgotten. This could lead to a situation where he has to convince the other demigods that this connection is important for the future of the camp. Maybe there are ancient prophecies that only he can understand due to his unique parentage.
Another plot could involve Percy having to prove himself to the children of Athena. Since he's not a child of Athena, they might be skeptical of his abilities at first. But as they face challenges together, like deciphering ancient prophecies that are hidden in Athena - related temples, Percy shows his worth through his quick thinking and battle skills. This could lead to a great friendship and mutual respect among them.
One idea could be Percy struggling to fit in with Athena's children at first. Since he's used to being a son of Poseidon, he has different ways of thinking and acting. Another plot could involve him using his newfound Athena - given wisdom to solve a really complex mystery in the demigod world. Maybe he discovers a new prophecy related to Athena that only he can understand because of his unique position as her adopted son.
One interesting plot idea could be Percy having to deal with the conflicting natures of his 'parents'. Since Gaia represents the earth and Poseidon the sea, he might struggle with controlling both earth - related and sea - related powers. For example, when he's near a beach, he could accidentally cause small earthquakes or make strange things happen to the sea life. Another plot could involve Percy facing a threat that only his unique dual - heritage can defeat. Maybe an ancient evil that is both of the land and the sea, and Percy has to figure out how to combine his powers in a new way to stop it.
One idea could be Percy having to face a new and powerful sea monster that is awakened by an ancient curse. He'd have to use his powers in unique ways, maybe even discovering new abilities as the son of Poseidon. Another could be Percy traveling to a long - lost underwater civilization that has a connection to his heritage as an ancient son of Poseidon.
One plot idea could be Percy discovers a hidden prophecy that involves his connection to both Poseidon and Hestia. He has to go on a quest to find an ancient artifact that can only be retrieved with the combined powers of the sea and the hearth. Another could be that there's a threat to the world where only Percy, with his unique parentage, can restore the balance between the elements of water and home/fire. For example, a dark force is causing chaos in both the underwater realms and the peaceful places protected by Hestia, and Percy has to use his skills and the powers he inherits from his parents to stop it.
A great plot could be Percy getting into trouble in the mortal world and Poseidon having to come to his rescue without revealing his true identity to the mortals. This would create a lot of tension and interesting scenarios where Poseidon has to use his powers subtly. Also, they could be on a mission to save a group of sea creatures that are being hunted by an unknown and powerful force. Poseidon could be teaching Percy about the importance of all sea life along the way.
A cool plot could be Percy being sent on a quest that involves mending the rift between Zeus and Poseidon. Along the way, he meets old foes and new allies. He has to use his wits and the powers he got from his fathers to convince other gods and demigods to support his cause. For example, he might have to show the children of Zeus and Poseidon that they can work together instead of being rivals.
One plot idea could be Percy struggling to live up to Poseidon's expectations as a demigod son. Maybe he has to prove himself in a series of trials set by Poseidon to show he can handle the power and responsibility that comes with being his son. Another could be Poseidon trying to protect Percy from the wrath of other gods who are jealous of their relationship. He could use his power to shield Percy from various threats, leading to some tense showdowns.