The Shade

While fighting against his brother Zareph in a civil war, Aedraxis pierced the barrier between the Planes, resulting in Regulos' power from the Plane of Death to manifest itself and annihilate the opposing armies as well as Aedraxis himself. This disaster devastated most of the Mathosians homeland in what became known as The Shade. Aedraxis was transformed into a being of incredible malevolence by this act, and many Mathosians followed their liege into the north.