They had always existed, since the time of when homosapiens first appeared. Even at that time we knew that conflict & differences would rise between men and thus war. To escape this catastrophe some good, wise and ethical people forged a Stargate out of matter that even today cannot be found on earth by modern man. Through that they ventured into the vastness of space to the very edge of the known universe to survive and thrive in peace, using the arts of magic to evolve. They hid the Stargate, the only surviving one on earth to the depths of Haye so that no evil troublemaker could find. Only to be used by any noble surviver born here on earth. The Seraphims thus became Gods and traveled to all over the universe with that Stargate through time and space.