Thunder Spirits (雷のスピリット) are a type of spirit summoned by Ashera to fight Ike's army. It is Thunder based and uses the exclusive weapon Thunder Tail. It and the other two spirits, Wind Spirits and Fire Spirits, are first seen in the fourth stage of part 4 endgame fighting with Sephiran, and then in the next chapter fighting for Ashera. They have the farthest movement range of any unit (20) and teleport around the battlefield. Although their element is Thunder, Dragons and Wyverns will not receive bonus damage when fighting them. They are the weakest of all three types of spirit, as thunder magic has lower damage and accuracy than wind or fire, the only bonus is the higher critical chances, which is irrelevant because spirit tails are incapable of critical hits.