Deal AOE damage on every 3rd attack

Cut from the limb of a rare creature that lurks in the fetid swamps of the west, Thunderclaws have long been a favorite weapon of the Beast Horde. The jolting energy within gives new agility to whoever holds one and inflicts searing pain on any enemy it strikes. In rare circumstances, some linkage of the wielder's own lifeforce and the necrotic Thunderclaw results in a blast of energy that electrocutes nearby foes.