The Divine War

The Heavens and the Hells had always influenced the material realm from their own domains. Manipulating the natural laws, bargaining with mortals and afflicting nature with boons and curses. The Hells were arguably better at this; able to corrupt the mortal races, who were drawn to power and comforts so easily. Eventually, when a small city was brought to its knees by a King corrupted by the promise of wealth and power the more his people grew greedy and suffered from it, an angel of Empyrean City could take it no more. Ithrial, Martyr of Justice, fell through the planes to Cupiditas, the plane of Greed. With such a surprise move from the usually rigidly honourable Celest, Ithrial slaughtered innumerable fiends on his rampage to the heart of Cupiditas, calling for a dual between himself and Athradaaki, Lord of Greed. For all of his confidence and wrath, Ithial lost the fight badly. He remains to this day, nailed to a bed of fire, tortured endlessly for all eternity. This act, an act of one individual, sparked an all-out war between the Heavens and the Hells. The centuries of remote influence were over; the time of invasion had begun.
Balance, one of the three primal powers of the universe, took no sides in The Divine War. An age of darkness fell on the material plane for hundreds of years as demons and devils became an almost common sight. Gods and celestials continuously fought them back and granted boons and miracles to those they wished to protect. Whenever one side gained too much power, Balance was there to fuel the forge of the opposing side while laughing at the amusement he caused himself. Eventually, the greed of devils was the Hells' downfall. The Hell's, always mattched in power with the heavens, instead sabotaged themselves, vying for power internally. The Heavens won the war by the skin of their teeth, and the material realm enjoyed a decade or two of complete prosperity. However, Balance didn't like this outcome.
For every boon or miracle that the gods placed on the mortal realm, Balance stoked the fires of Hell's forges. New evil powers rose up, threatening the prosperity that the Heaven's had worked so hard to secure. Aegwyn, Goddess of Empyrean City, the pinnacle of the heavenly realms, called a counsel of the other upper realms. The Alliance of Light was formed. most of the heavenly realms joined in a singular, selfless goal; don't act; do nothing. The material realms were happy, for the most part, and to affect them further would be to allow Balance to play his game of fueling the weaker side. Eventually, the realms that joined the Alliance of Light were almost forgotten by the mortal races.
In the present day, something is wrong in Balance's domain. The Hells are growing in power, yet the Heavens remain devoid of his fuel. With this information, Aegwyn, ruler of what was the pinnacle of the Heavens, has decided to act. If Balance has been compromised then she will build a following, and from that following, an army the likes of which the Hells haven't seen in all of eternity.