When inducted, each Ancient makes a pact with the Dark Lords of the House to split portions of each soul they take in death. The Ancient gains some part of the soul for their own power, to be converted into gems and other uses. The rest of the soul is stored in the Altar of the Ancients for use by their Dark Lords.
However, the Dark Lords turned away from the Ancients in pursuit of their own endeavors, tiring of the weak souls the Ancients had been regularly gathering. Left alone for years upon years to stew within their confines, the pieces of souls gathered in number and in strength. Their collective anger, rage, and sorrow welled up within the Ancient Altar until finally, one day, they had enough power to burst past its confines and hurdle across Thera.
A long and powerful battle waged between the whole of Thera and those of the very dead variety. Each standing house was tested by the very spirits that once lived within them. In the end, the Knights of Valor, the Knights of the Legion Army, and the very killers that trapped the souls -- the Hunters of Ancient -- were all destroyed.
The ripples across the cosmos from this destruction at the hands of the angry souls made a small tear in the Veil. Like attracted like, and dark souls rushed out from the Veil to join the freed souls. Efforts were made to mend the Veil and return the spirits to their rightful place beyond it. However, some individuals preferred instead to leverage the torn Veil.
What rose from the ashes of conflict was a new power. Some say they are witch doctors, while others would simply call them the Depraved. This new power harnesses the spiritual energy within the broken Veil and uses it to do their bidding. They have been known to travel between spiritual totems, hex enemies with a powerful staff, and corrupt the very being of Theran citizens.
Their mission is simple: Spread the influence of the dead and dark, the spirits and demons of our imaginations from beyond the Veil.