Spirit of Light

The Spirits of Light are the four spirits that watch over each of the four different provinces of Hyrule in Twilight Princess. They guard the provinces of Ordona, Faron, Eldin, and Lanayru. All four are named after the province they guard, or possibly vice versa.

History
The Light Spirits were set to Hyrule to contain the Light that sustains Hyrule. When Link restores the light to Lanayru Province, Lanayru tells the legend of the Twili. Long ago, a tribe of Dark Interlopers who excelled in the dark magical arts tried to establish dominion over the Sacred Realm in order to gain the power of the Triforce. However, the Gods asked the 3 Light Spirits to intervene. For some reason the spirit of Ordona was not included in these 3, maybe due to it not being part of "Hyrule Proper", or it may have been that Nintendo just forgot to include Ordona in the event. The Light Spirits sealed away the tribe's magic into the Fused Shadow and the interlopers were chased across Hyrule into the Gerudo Desert. It was then the Tribe was banished into the Twilight Realm by the Gods at Arbiter's Grounds, to be sealed away forever. However, the Gods left one link between the two worlds, the Mirror of Twilight, which was to be guarded by the Six Sages.

Only people who are brave can see them. In fact, the only known people who are known to be able to see them are Link, Zant and, even though she would be gravely injured by the light, Midna.

In Twilight Princess, Link has to rid the land of Hyrule from the twilight by restoring the Light Spirits Faron, Eldin and Lanayru, through collecting Tears of Light scattered across each province. The Light Spirits prove essential in Link and Midna's quest to find the Fused Shadows, as only they seem to have knowledge of where the dark objects are located. The Light Spirits also appear in the final battle against Ganondorf as they combine their powers to create arrows of light. After Ganondorf is defeated, they appear before Link and Zelda, seemingly having resurrected Midna.

The spirits as they appear in order to Link:
 * Ordona appears as a goat.
 * Faron appears as a lemur or a monkey.
 * Eldin appears as a moth or an owl.
 * Lanayru appears as a serpent.

Trivia

 * Ordona is the only Spirit of Light that is not named after a goddess (Faron is named after Farore, Eldin is named after Din and Lanayru is named after Nayru).
 * While the Twili and their related artifacts tend to have structured, inorganic patterns, the Spirits of Light and Light objects are covered in curved and flowing markings. The difference in structural imagery serves as additional visual constrast between the two opposing sides in Twilight Princess.