Zethes

Zethes is a son of Boreas and a mortal. He was a demigod until his father offered him and his demigod brother Cal. He travelled to retrieve The Golden Fleece with the original Jason. His sister is the goddess of snow Khione.

The Lost Hero
He is said to look like a love god from the 70's. He is at his father's palace when Jason, Piper and Leo go there to get information from him.