Fair question. The interpretation I chose is that he was one of the Watchers from the Genesis 6 conspiracy, which is expanded on in the Book of Enoch. The group of fallen angels tried to usurp the children of Adam's dominion on earth by claiming to be gods, and marrying the daughters of men in exchange for forbidden knowledge which the humans of the time were trying to learn. This gave rise to the nephilim (giants) which ruled the earth from human thrones for a while until the flood wiped them out. These were "mighty men of old, men of renown," analogous to Greek heroes. The Watchers were pretty high ranking angels. Power wise, he should be on roughly the same level as an Asura or Titan.

Edit: the abilities are based on a combination of the punishments of the Watchers, the Hebrew rituals surrounding Azazel (imputing the sins of the Israelites onto a goat for sacrifice), and the theme of "scapegoat" in general.