Event on Colossal Cavern

You confront Wyrminthal, Lord of the Warlocks. "Art thou the interloper of which the great Drakes speak? The slayer of Dragonnes and banisher of the Undead?" his voice booms from the castle ahead. "If thou art here for the treasures of old, thy quest is at end. But so is thy life!" His grim visage hangs before your armies, inspiring dread.