After an unsuccesful attempt by Beast-Man to get the power sword, Skeletor realises that no living creature with evil inside them will never be able to hold the sword of power.  Thus, he gets his Skelcons to create a new Master of the Universe, one made completely of iron.

Despite the best efforts of the heroic warriors, The Iron Master succeeds in capturing the sword of power, only to in turn be defeated by the elements, as lightning is attracted to the sword, and feeds down into The Iron Masters body, melting him!