This is not the real Son of Neptune. I know that Rick Riordan will do a WAY better job but I had a few ideas.
Percy:son of Poseidon
Annabeth:daugther of Athena
Leo: son of Hephaestus
Piper: daughter of Aphrodite
Nico: son of Hades
Butch: son of Iris
Will Solace: son of Apollo
Jason: son of Jupiter
Hazel: daughter of Neptune
Gwen: daughter of Pan
Reyna: daughter of Mars
Bobby: son of Apollo
Thalia: leader of Greek hunters/ daughter of Zeus
Allison: daughter of Pluto
Sally: daughter of Properpina
May: daughter of Ceres
Joel: son of Kronus
Annabel: daughter of Minerva
Emily: daughter of Hestia
Cole: daughter of Thanatos(death) Nico's helper
Samantha: leader of all hunters/ daughter of Terra
Melissa: leader of Roman hunters/ daughter of Helios
Sorry if there are a lot of characters but at least I keep you posted. I might delete a few.