On the other hand, Paul could be surprisingly accepting. Maybe he has an open - minded nature. He could see the good in Percy and his friends, and want to support them in their adventures. He might even be curious and start to learn more about the demigod world.
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.
Well, if Paul finds out in the fanfiction, he might be shocked at first. He could react in different ways depending on what he finds out exactly. Maybe he discovers Percy's true identity as a demigod. He might try to protect Sally more, or he could be scared and want to distance himself from the whole situation.
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.
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.
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.
In a 'Percy Meets Paul' fanfiction, Percy could be a demigod, like in the Percy Jackson series. He has powers related to the Greek gods. Paul, on the other hand, could be a normal human who is very intelligent and curious. Their meeting could be a chance encounter, like Percy accidentally stumbling into Paul's life while on a mission. Or Paul could be someone who has been unknowingly drawn into Percy's world of magic and mystery.
Well, in some versions, Percy might be initially shocked. He could be like 'Whoa, I had no idea!'. Then he might start to see Nico in a new light, with more understanding and compassion.
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.
He could be shocked at first. Just the sight of the scars might make him realize that Percy has been through a lot more than he thought.
She might be shocked and feel a great deal of sympathy for Percy. She could immediately try to comfort him and assure him that he's safe now.
Poseidon might be extremely angry. He could immediately seek revenge on the abuser. After all, Percy is his son and he has the power to protect him.