Paul could react with disbelief. He might think it's all some sort of elaborate joke or Percy's wild imagination. After all, the idea of demigods and Greek gods being real is quite far - fetched for a normal mortal like him.
Obviously, Paul and Percy are going to be main characters. Paul, as the one who finds out Percy's big secret. Percy, being the demigod whose secret is revealed. And there could also be other characters from the Percy Jackson series like Annabeth. She might be involved in helping Percy deal with Paul's discovery, either by giving advice or by being there to support Percy emotionally.
In some fanfictions, Paul could end up getting involved in the demigod world himself. Maybe he discovers he has some latent powers or a connection to the gods. This would completely change his perspective on life and his relationship with Percy. He could become a mentor figure for Percy in the mortal aspects of dealing with his demigod status.
His first reaction might be shock. Dragons aren't exactly common in his world, even with all the mythical creatures. But then his hero instincts would kick in. He could try to befriend the dragon, thinking it could be an ally in future battles against the Titans or other enemies. He might offer it some food, like a fish or something, to gain its trust.
Paul might be characterized as the voice of reason. In a world full of chaos and mythical beings, he can be the one who tries to find logical solutions. He could be a bit of an amateur detective in the fanfiction, using his teaching skills to research and figure out things related to the demigod world. Also, his relationship with Sally gives him a deeper connection to Percy and a motivation to be involved in the demigod's life, so his protective side towards Percy can be emphasized.
Perhaps the baby has some unique powers. Percy finding the baby could be the start of a whole new adventure. He could take the baby on a journey to find out more about its parents. Along the way, they might encounter old enemies of Percy's or new threats. The baby could also form a special bond with Percy, and as it grows, it could become an important part of the demigod world. Percy would have to teach the baby about the world of gods and monsters, and how to survive in it.
The baby might be a key to a long - forgotten mystery. It could be related to an ancient pact between the gods. Percy finding the baby could be a sign that something big is about to happen in the world of the demigods. The baby's identity could be slowly revealed as Percy and his friends investigate. It could be a symbol of hope or a harbinger of doom, depending on the circumstances surrounding its appearance.
One great fanfiction with this theme is 'Soulbound'. In it, the female Percy Jackson character goes on a journey that leads her to meet a character who becomes her soulmate. The story is full of adventure, just like the original Percy Jackson series, and the relationship development is really well - written.
Yes, there are quite a few Percy Jackson fanfictions that are really good. One kind that's popular is the 'what if' scenarios. What if Percy had joined a different camp? What if he had made different choices during his quests? These types of fanfictions can be really interesting as they show different possible paths for the characters. There are also fanfictions that introduce new characters that blend well with the existing ones, adding new layers to the story.