The Elements of Nature trilogy

The Elements of Nature is a series of stories about a unicorn named Firebrand, who has the ability to control, or "bend" fire. He, along with the main six, the CMC, Shining Armor, and Princess Cadence, get caught up in a war where they must find 4 others who have similar abilities so they can restore the balance of the world before the return of Sozin's Comet.

Summary
Long ago, before the regal wing unicorn sisters were born, the world was protected by a powerful being called the Avatar. The Avatar was the only one able to control all the Elements of Harmony at once, but he is also able to control their counterparts, the Elements of Nature. Only five of the Elements of Nature are known, the known ones are fire, water, earth, lighting, and air. Like the Elements of Harmony, the Elements of Nature have physical form, but they are also part of the Avatar’s sole. Because of this, he or she is able to control each element with relative ease, even if they are thousands of miles apart. The Avatar is also the only one who can communicate to the Spirit World, listening to the Spirits’ guidance to keep balance in the world. Whenever the Avatar dies, his or her soul is reincarnated into a new body. Each time he is reincarnated he becomes one of the 4 types of ponies in a cycle in this order: Unicorn, Earth Pony, Pegasus, and Alicorn. Then one day, for no apparent reason, the last Avatar, an Alicorn named Roku, the father of Celestia and Luna, vanished. No one knows what happened to him. An ancient prophecy states the will return, but in five different bodies, each representing a different element. Most have considered the Avatar as a bedtime story, but some believe he will return one day to return balance, and that day has finally come.

Characters
Firebrand: The Avatar of Fire

Agua: The Avatar of Water

Terra: The Avatar of Earth

Blitz: The Avatar of Lighting

Ar: TBA