In the beginning, before anything else had come into existence in reality, there was The One, a being of infinite power, However, having no reality in which to understand itself, it could not stay as The One, and dissolved itself into a finite amount of nebulous energy in the void of space and time.
Over time, this energy, which we will refer to as "Origin energy" developed into thousands of individual beings, who we will temporarily call the "Daevans". These beings also lacked an environment in which to understand themselves, their minds blank slates in which nothing was present. However, from their beings slowly flowed an eternal supply of "Creation energy", The energy from which all other matter and energy is formed.
Soaking in this primordial nebula of energy, entire realities blossomed and withered, the Daevans slowly developed their beings and forms while learning about themselves and their place in the universe, in peace and curiosity.
Over time, the Daevans emerged from their individual realities, bringing with themselves many of the native creatures as protectors, and met each other. Amazed by the fact that there were others of their kind, the Daevans formed an inter-dimensional Utopia among the glimmering pieces of reality, all of their creatures living in peace and harmony with each other and the Daevans. It was a time of complete perfection, expression, and unparallelled vibrancy, the creativity of the Daevans emanated from their utopia, benefiting all of reality.
However, There were others of their kind who had not been so lucky as to make it out of their individual realities. On the outskirts of existence, the ancient and forgotten realities of the abandoned Daevans shattered, broken open by unknown beings from the void. The stunted and monstrous Daevans of the old realities, having been freed from their prisons, began to tear through reality, assisted by these beings of the void.
Eventually word of this got the the Daevan of Utopia, and they set out to put a stop to the terrible destruction being wrought throughout reality by the hostile Daevan and their benefactors.
The story would be based around the time period at which A few of the Daevan volunteer themselves and their creatures to the task of putting an end to the events happening out in reality.
(Note: The Daevans themselves are around human intelligence, and generally at least slightly good natured, and not really gods in terms of up-front power. This is one of the many reasons they have their own races of creatures that they care for.)
My only problem is, I don't know how to execute something of this scale. But what do you think of the idea itself? This is only the very rough outline, without any details worked out. I'd like to collaborate people on the details...