Vaati

The villain in The Legend of Zelda: The Minish Cap and the The Legend of Zelda: Four Swords. Vaati is a Wind Mage, and is seen taking on two main forms, a humanoid and a monster (much like Ganon and Ganondorf).

The Minish Cap
The origin of Vaati is told in the adventures that Link faced with the Minish Cap. Originally of the Minish race, Vaati was fascinated by the evil that could come from the heart of man. When his master, Ezlo, fashioned a powerful cap as a gift for the humans, Vaati stole the cap, and transformed his master, so that he would not stop him. Then, taking human form, Vaati set out to find the means to allow him to become the greatest sorcerer the world had ever seen.

The Four Swords
Released from his prison within the Four Swords, Vaati kidnaps Princess Zelda, forcing Link to go off and search for the princess. After Link rescued Zelda and sealed Vaati in the Four Swords, Hyrule was at peace, until Ganondorf stole the Dark Mirror and created Shadow Link to kidnap Zelda and the Shrine Maidens and trick Link into releasing the Four Sword and releasing Vaati. During Link's adventure to save Hyrule he found out that Vaati is not the real enemy, he found out Ganondorf created Shadow Link to trick Link into releasing Vaati to distract Link So Ganondorf could steal the Trident to transform into Ganon and take over Hyrule.