Forces of the Heavens
Creation Myth
In the beginning there were thirteen gods. Twelve of them each claimed that they could create the best kingdom, and thus the twelve kingdoms were born. The thirteenth god was young and impulsive and wasn't allowed to create a kingdom. Jealous, he created demons to destroy the creations of the Twelve.
For his horrible act, the thirteenth god was named the god of destruction and banished to the Nether, a realm that has been his prison ever since. The god of destruction did not go without a fight and ended up erecting an impenetrable barrier between the Heavens and the mortal realm, preventing the gods from interacting with mortals directly.
Now, demons spawn in the mortal realm to destroy whatever they can, with little to stop them but the mortals themselves.
Angels
Angels are the only proof mortals have that the gods even exist still. They act as messengers for the gods and can freely pass through the barrier between the Heavens and the mortal realm. It is rare for the gods to have messages for mortals, so more often than not, the angels either lead the fight against the forces of Hell or have agendas of their own.
All of the angels were once mortals who ascended either by being granted the power by another angel, or by killing an angel and taking their power. As such, angels are not necessarily forces of good.
Regardless of how they ascended, angels retain the names, identities, personalities, appearances, and motivations of who they were as mortals. So, if a wicked person ascended, they would likely remain wicked.
The War with Hell
The Heavens and Hell have been at war with each other for as long as anyone can remember. When the gods created Hell and the devils, the intent was for the devils to punish souls who had done evil.
For a time, the devils stuck to their roles as Hell's prison guards, but eventually, the power went to some of their heads. Many of them started killing mortals and taking the souls of those undeserving of damnation. The Heavens were not pleased. Ever since then, the two forces have been enemies in a never-ending fight, even the devils who refused to steal souls.
By divine law, it is impossible for angels and devils to kill each other, so the majority of the actual violence takes place between holy crusaders and devil cultists. That said, angels and devils will often lend a hand to their side of the battle in the form of blessings or favors.
