Well, perhaps the story could revolve around how Percy and Reyna adjust to their new roles as parents. They could struggle with balancing their duties in the demigod world and taking care of their little one. Maybe they have to seek help from their friends in Camp Half - Blood and Camp Jupiter to keep the baby safe and happy.
Maybe in the fanfiction, Percy and Reyna meet during a time of peace. They initially bond over their shared love for their respective camps. They decide to exchange knowledge, Percy teaching Reyna some of the more unorthodox combat techniques he learned from Poseidon, and Reyna teaching Percy about Roman military strategies. As they spend more time together, they also help each other deal with personal issues. Percy helps Reyna open up more about her feelings towards her sister, and Reyna helps Percy better understand his role as a hero in a changing world. Their friendship grows as they support and understand each other more deeply.
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.
One possible plot could be that the baby has unique powers. Since Percy has his demigod abilities and Aphrodite is the goddess of love, the baby might be able to manipulate emotions in a very powerful way. Maybe the baby is initially a mystery to the demigod community, and Percy has to protect it from those who might want to use its powers for evil. As the baby grows, it also starts to show an affinity for water like Percy, but with a touch of Aphrodite's charm, being able to make even the most violent waters calm with its presence.
One possible plot could be that Percy is being controlled by some dark force. Maybe a new evil god or an ancient curse. This force makes him kidnap Reyna because she has some important knowledge or power that the dark side wants. For example, she might know the location of a powerful weapon that could tip the balance in a coming war between the gods and the titans' remnants. Percy, against his will, takes Reyna to a secret location. Reyna, being a strong and resourceful character, tries to figure out a way to break Percy out of the control while also dealing with the situation at hand.
One possible plot could be that after years of adventures and growing closer as friends, Percy and Reyna start to realize they have deeper feelings for each other. They might face some initial resistance from their friends who are used to them just being comrades. But as they work together on a new mission, their bond strengthens and they finally decide to get married. The wedding could be a grand affair with all their demigod friends in attendance, celebrating their union.
Their relationship would likely become more centered around the baby. They'd have to communicate more about parenting decisions.
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.
One possible plot could be that after a great battle, Percy and Reyna find themselves drawn to each other more than ever. They start to work together on rebuilding their world, and during this process, their friendship blossoms into love and they decide to get married.
One possible plot could be that Percy and Reyna are betrayed by their closest allies within the demigod community. Maybe they are framed for a crime they didn't commit, like stealing a powerful artifact from the gods. Their friends turn against them, believing the false accusations. Percy and Reyna then have to go on the run, trying to clear their names while also facing various threats from the gods who are angry about the supposed theft.