Vaati

Vaati is a Wind Mage, and the villain in the Four Swords subseries of The Legend of Zelda games along with The Minish Cap. Vaati is seen taking on two main forms, one a human, the other a monster (much like Ganondorf and Ganon). In The Minish Cap, Vaati also has a third form between his human and true demon form, namely that of a humanoid demon sorcerer that somewhat resembles a Patra from the original Legend Of Zelda.

The Minish Cap
The origin tale 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 magical cap as a gift for the humans, one that could make one's wishes come true. Vaati stole the cap, transformed into a sorcerer and cursed his master into the shape of a living cap, 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.

He found that means in the legends of the Light Force, a mystical magic said to bestow upon the wielder the powers of godhood. Over the course of the game, Vaati continuously sought its location, finding it in the end in the most unlikely of places, within Princess Zelda. Vaati managed to extract some of the Light Force from Zelda and transformed into a tall sorcerer form known as Vaati Reborn. Link defeated the form with the power of the Four Sword, and Vaati transformed into a demonic one-eyed black orb known as Vaati Transfigured, but was vanquished again. In his anger, Vaati transformed yet again, into a larger, more powerful version of this form known as Vaati's Wrath, but even this could not defeat Link, who sealed Vaati within the Four Sword. Zelda then proceeded to use the magical cap to restore what Vaati had done, destroying the cap in the process.

Vaati's Five Forms
In the game, Vaati is seen in a total of five forms; a Minish, a human, a demonic sorcerer, a wind mage, and a true demon form.

Quote from The Legend of Zelda: The Minish Cap Minish Vaati figurine: "Before he became a sorcerer, he was a simple Minish. He had always been entranced by the evil that lives in the hearts of men.."

Quote from The Legend of Zelda: The Minish Cap Sorcerer Vaati figurine: "When the young Minish donned Ezlo's magic cap, he took this evil form. Now, he searches for the light force in his quest to become all-powerful."

Quote from The Legend of Zelda: The Minish Cap Vaati Reborn figurine: "The sorcerer Vaati took this form after draining the power of the light force from Princess Zelda. The evil beams from his eyes are devastating."

Quote from The Legend of Zelda: The Minish Cap Vaati Transfigured figurine: "Once Vaati's body has been shattered, this dark form rises up, all that remains of the evil sorcerer. Only the sacred Four Sword can defeat him."

Quote from The Legend of Zelda: The Minish Cap Vaati's Wrath figurine: "This is the embodiment of purest evil, the final form of the power-mad Vaati. It's mind is consumed with a hunger for destruction. Find it's weakness." It should be noted that his horns in this form look like Midna's tiara, which she wears in her true form.

The figurines for Vaati's boss forms are hidden. They cannot be won in the figurine lottery without first defeating Vaati.

Four Swords
The seal on Vaati was apparently weakened over time, and a long time later Vaati managed to break out of his prison within the Four Sword. Vaati kidnapped Princess Zelda, forcing four Links to go off and search for the princess. After traveling over three different lands and the dungeons they contained, Link and his three other selves confronted the wind mage in the Wind Palace, the seat of Vaati's power. After a arduous battle between the sorcerer and the heroes, Link was able to reseal Vaati into the Four Swords blade.

Four Swords Adventures
After Link had rescued Zelda and sealed Vaati in Four Swords, Hyrule was at peace for a time. This changed when Ganondorf stole the Dark Mirror from the Temple of Darkness. Creating Shadow Link to kidnap Zelda and the Shrine Maidens, Ganondorf tricked Link into releasing the Four Sword, unsealing Vaati in the process.

During his adventure to save Hyrule, Link found out that Vaati was not the real enemy. Instead, Ganondorf had instigated the ordeal with Vaati to distract Link, allowing Ganondorf the time needed to steal the power of the Hylian Shrine Maidens.

Over the course of the adventure, Link rescued the Shrine Maidens and Zelda, and restored his good name upon defeating Shadow Link with Zelda's help. At the final battle, Link and his split selves defeated Vaati, and sealed Ganon within the Four Sword with the help of Zelda and the Shrine Maidens. With this, peace returned to Hyrule, and the Four Sword was laid to rest in its shrine. With this being the last tale in the Four Swords era, Vaati was supposedly finally destroyed in this game. Whether he actually destroyed Vaati, or merely sealed him inside the Dark World, is unknown.

Trivia

 * The wanted poster in Ocarina of Time's Shooting Gallery bears some resemblance to Vaati's Wrath.