Ourelonastrix was a powerful blue dragon from the Age of Demons and legendarily the first wizard, who alongside the couatl Hezcalipa discovered the Draconic Prophecy. Ourelonastrix was instrumental in the conflict against the Overlords, as victory would not have been possible without the discovery of the prophecy.
It is possible (and indeed likely) that Ourelonastrix inspired myths of the Sovereign Host, in particular myths around Aureon. It was the students of Ourelonastrix that taught the giants to use magic, which in turn trickled down to other mortals learning to use magic as a tool, which is consistent with what the Vassals believe were the actions of Aureon.
Some draconic scholars theorize that Ourelonastrix learned magic from one of the Overlords, most likely Bel Shalor, the Shadow in the Flame or Sul Khatesh, the Keeper of Secrets, which could have inspired myths of The Shadow. After the dragons razed the continent of Xen'drik, they began referring to Ourelonastrix's tutelage of the giants as kurash Ourelonastrix, or "Aureon's Folly" in Common.