Double Trouble

A terrible storm uncovers a secret passage in Snake Mountain, which leads to a magic mirror that can make a double that works opposite from its original out of anyone. Skeletor capture one of He-Man's allies to make an evil double out of, so that the double can steal the secrets of Grayskull for him. However, when the ally thinks of a clever way to make a good double of Skeletor, it is up to that double to fix the trouble that the real Skeletor has caused.