The holy energy that flowed through Coba Plateau manifested itself in the form of the holy weapons. The goblins tried to make a quick buck by auctioning them off to the Empire and the League.
Little did they know that the Light was being replaced by darkness, thanks to the cultists. This only made the artifacts more expensive, and they were highly sought after for their powers.
This zone's world mystery, Holy Weapons, shows the bad side of the factions. When power exists nobody cares where it came from. Blood, death, despair... they become meaningless.