Demogorge is the overpowered form of the ancient god Atum, son of Gaia, elder Goddess of the Earth, and therefore another half-brother of Thor. Sensing that her elder god brethren were degenerating into demons, Gaia mated with the Demiurge - the sentient life force of Earth - and gave birth to Atum, who devoured many of the elder beings, two exceptions being Cthon and Set. Having devoured all demons, he expelled their life force, which eventually coalesced again into a new generation of gods.