Vaati

Vaati is the main Villain in the Four swords sub series of the Legend of zelda. His most seen form is a floating god eyeball like creature, but he has other forms as well.

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.

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.

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.

Vaati has two forms in this game. The first is Vaati possessing a statue of himself, encased in armor, similar to the Vaati's Transformation form from later in The Minish Cap. In the second form, he appears as he does in the opening cutscene, and the battle is very much like the battle against Cyclok in the later Phantom Hourglass.

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 (Who apparently vanished in black smoke with a deep laugh), 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.

It is unknown whether this Link is the same one from Four Swords or not because a few things have been changed like Link having a Red Shield in Four Swords Adventures and a Blue Shield in Four Swords and the Link in Four Swords sounds like the Link from Majora's Mask and the Link in Four Swords Adventures sounds like the Link from The Wind Waker.