One interesting plot could be Percy having to prove himself to Poseidon in a new and unexpected way. For example, he might have to solve a mystery that is directly related to Poseidon's power over the sea but in a realm that is unfamiliar to both of them, like an underwater civilization that has been lost for centuries.
Another plot could be Poseidon getting involved in Percy's love life in a very hands - on way. Maybe he thinks a certain person is not right for Percy and tries to set him up with someone else, which causes all sorts of comical and tense situations as Percy tries to navigate his own feelings while also respecting his father's wishes.
A plot might also involve Percy and Poseidon teaming up against a common enemy that is threatening both the mortal and the divine world. This could lead to some really cool action scenes where Percy uses his unique demigod skills and Poseidon uses his godly powers in a coordinated effort.
A great plot might be that Poseidon has to protect baby Percy from other mythological beings who sense his potential power. So he hides Percy in a special place where only he can find him. This could lead to all kinds of adventures as Poseidon has to fend off threats while keeping Percy's existence a secret.
One possible plot could be Poseidon teaching Percy about his underwater powers in a really fun and father - son way. For example, they could have little adventures in the ocean where Poseidon shows Percy how to communicate with sea creatures. Another plot might involve Poseidon protecting Percy from the other gods who are jealous of Poseidon's special relationship with his son. Maybe he creates a hidden underwater lair for Percy to grow up safely.
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.
One possible plot could be Percy sacrificing himself to save his friends while in Poseidon's arms. Maybe there's a great battle against an unbeatable foe, and Percy realizes the only way to victory is through his own death. He accepts his fate in Poseidon's comforting embrace.
One possible plot could be Poseidon's grief and his journey to seek revenge for Percy's death. He might use his power to disrupt the world that allowed such a thing to happen. Another could be Poseidon trying to bring Percy back to life, going against the rules of the gods and facing many challenges along the way. Or perhaps Poseidon watches as the world changes after Percy's death, seeing how the other demigods step up or fall apart without Percy's leadership.
Well, a plot might involve a love triangle where Poseidon and Athena both fall in love with a mortal. Their rivalry for the mortal's love then turns into an understanding of their own feelings for each other. Or perhaps there's a story where they are trapped in a magical realm and have to rely on each other for survival, and in the process, their love story unfolds.
One possible plot could be that Poseidon and Aphrodite meet secretly in an underwater grotto. They share their frustrations about their roles in the pantheon. Poseidon might talk about his often - stormy relationship with other gods due to his control over the seas, while Aphrodite could speak of the pressures of being the goddess of love. Their friendship could slowly turn into love as they discover they have more in common than they thought.
A really unique plot could be that Poseidon and Medusa's love is a way to bring about change in the world of the gods. Their union could be seen as a symbol of breaking free from the traditional norms. Medusa, with her unique powers, and Poseidon, with his vast influence over the seas, could team up to create a new era. However, they face many obstacles like the jealousy of other gods and the strict rules of the divine hierarchy.
One possible plotline could be that Percy has accidentally angered Poseidon by misusing his powers in a way that Poseidon deems irresponsible. For example, he might have used his water - controlling abilities to create chaos in a mortal city without proper justification. Another could be that Percy has broken an ancient underwater law that Poseidon is bound to enforce. Maybe he revealed a secret of the underwater world to mortals which is strictly prohibited.
One plot idea could be Percy having to go on a quest specifically guided by Poseidon's hidden messages in the sea currents. He has to decipher these messages to find a lost artifact that can save the underwater kingdom from a new, mysterious threat.