To approach Zalmoxis, we start from Apollo. God of Forecasting. God of Diseases, Supreme Healer. Magician Sire of the Underworld, God of the Far Traveling Arrow. He is not Greek, he came from the immense plains in the North-East, from lands where the Sun rises and lasts.
Bloodthirsty Apollo craves for bloody offerings. His ancient priests, magicians themselves, came to Greece from this same distant vastness, where the Sun does not set, but merges into the same limitless land, as infinite as an Ocean. Their ancient Greek name was: Hyperboreans. Zalmoxis was counted among the hyperborean magicians. According to ancient fragments, he taught men the prolongation of life.
He might dispense immortality