In the beginning, the Balaur, a powerful race of servitors created by the god Aion roamed the world of Atreia. However, their own will led them to disobey Aion's wishes and they rebelled against their creator. Aion then created another race, the Daevas, and even though they were less powerful as individuals then the Balaur, Aion gave them a sense of loyalty and worship towards himself so they would obey him in all matters.

The Daevas fought with the Balaur and expelled them from the world Atreia into a different dimensional plane. For a time there was peace. But the Daevas, though all loyal to the god Aion, had different views regarding the Balaur which ultimately led to them splitting into two different Factions. One part of the Daevas wanted to end the eternal war with the Balaur and try to make peace, while the other side wanted to fight until the end.

The Balaur offered a peace treaty but through a betrayal (that has not yet been elaborated on), the Balaur were led to attack the Tower of Eternity, the physical representation of the god Aion, and destroyed it, causing a big catastrophe that brought destruction upon the world and split the Tower of Eternity into two pieces. Now Atreia is separated into two halves with one remaining half of the tower on each part of the world.

The lower part of the world is inhabited by the Elyos and is blessed with sunlight, the upper half, inhabited by the Asmodians only receives a fraction of the sunlight. Because of this separation both factions have become bitter enemies, blaming each other for the destruction of the Tower of Eternity and their world, and each side believes they have to destroy their opposition to ensure their own survival.

Now, a three-sided war is waging between the Elyos, Asmodians and the Balaur, with the main focus for each faction being the control of the Tower of Eternity. Communication between the god Aion and the Daeva has ceased, and while nobody knows what happened to the god Aion after the tower was destroyed, both factions know they have to prevent their part of the Tower of Eternity to be destroyed in order to ensure their survival.

The player is taking the role of one of the leading characters of each faction, starting out as lowly soldiers, eventually realizing their power and potential, becoming more and more powerful and rising in the ranks of their race's military to eventually become Generals of the army they fight for in this three-sided war.