When the god Aion created the world of Atreia, he created the draken—powerful dragon-like beasts tasked with safeguarding the humans; performing Aion's will on the planet; and protecting the Tower of Eternity, Aion's physical presence on Atreia. For a time, the draken obeyed Aion; but over time, they began to enjoy their power, ignoring their duties and abusing the humans. Aion took notice, creating the twelve Empyrean Lords in response. Angelic in appearance, the Empyrean Lords were demigods who walked amongst humans, and used a force called "Aether" to create a powerful barrier around the Tower of Eternity, protecting all of those within. While the outside world continued to be ravaged by the draken, who had become the more ferocious Balaur; the humans within the barrier managed to tap into the Aether, gaining their own powers. In time, they would become known as the Daeva.
Aion is an amazing game with breakthroughs in Flight Physics and a well, developed storyline and world.