One possible plot could be Percy as a baby merman being discovered by a kind fisherman. The fisherman, instead of harming him, decides to protect Percy and hides him in a secret cove. As Percy grows, he starts to show unique powers like being able to communicate with sea creatures even at a young age.
A young mermaid named Ariel could be a main character. She could be Percy's friend and help him explore the underwater world. She could teach him how to swim faster and find the best hiding places from the bigger sea creatures.
In the fanfiction, if Percy is turned into a baby, it could be a really heart - warming story. Maybe the story starts with Percy suddenly transforming into a baby right in the middle of an important event. His friends are shocked but quickly spring into action. They take him to a safe place and start trying to figure out what happened. As they take care of him, they learn a lot about themselves too. For instance, one character might discover their nurturing side. And Percy, even as a baby, might show signs of his future heroic self, like being fearless in the face of small challenges or showing an unusual affinity for water, which could be a hint at his powers.
In the fanfiction, Poseidon's visit to baby Percy could be a very solemn occasion. Poseidon, being a god, has to be careful as his relationship with Percy's mother is against the rules of the gods. He might come to bestow some of his godly essence on Percy, which would explain Percy's natural affinity for water. He could also be there to make sure Percy has a chance at a normal life for as long as possible, so he might use his powers to hide Percy's demigod scent from other monsters for a while.
Maybe the plot focuses on how Percy and Hestia adjust to being parents. Percy, who is used to his own adventures, now has to think about the safety and upbringing of a child. Hestia, on the other hand, has to deal with the new dynamic of having a half - mortal baby. They might face challenges from the other gods who are not happy about this union and the existence of the baby.
Well, one possible plot could be that their baby has some sort of unique power. Since Percy is a demigod with special abilities like controlling water, and Hera is a powerful goddess, their child might inherit a blend of powers. Maybe the baby has the power to control the weather, as it combines Percy's elemental connection with Hera's association with the sky. This could lead to all sorts of adventures where the baby has to learn to control its powers while facing threats from other mythological beings who are either jealous or see the baby as a threat to their own power.
Well, it could be that the gods, being curious about this special baby Percy, come to visit him. Maybe they bring gifts like in the story of baby Hercules. They might see his potential and start to argue among themselves about his future role in the world of demigods.
Well, a cool plot might be that there's a merman who has a special power to control water currents, and Percy needs his help to find a lost magical artifact deep in the ocean. In return, Percy has to help the merman get accepted by the surface - dwelling gods. Or perhaps a merman is wrongly accused of stealing Poseidon's trident and Percy has to prove his innocence.
For sure Percy. A merman who is an outcast among his own kind because he has a unique ability that others are jealous of. And Nico di Angelo could be another main character. Nico's connection to the underworld might play an interesting role when dealing with the merman's world which is so different from the underworld but still has some similarities in terms of being a hidden and often misunderstood realm.
Perhaps the story could be about how Percy and Annabeth adjust to parenthood. Annabeth might be overly cautious because she's used to planning and strategizing, while Percy is more laid - back. Their different parenting styles could lead to some humorous and also some tense moments. The baby could also start showing signs of being a hero from a very young age, like having an uncanny ability to find lost things, which is a sign of the baby's connection to the demigod world.
One possible plot could be that Percy and Zoe face many challenges in raising their baby. Maybe they have to protect the baby from mythological threats. Since Percy has his powers and Zoe was a huntress, they'd use their skills to keep their family safe.