A big part of inspiration comes from ancient myth and legends of our own world. Old Religions and ancient stories about legendary cities like Atlantis or creatures like Demons and Angels. What if these myths are all true, but just misinterpreted by the people of the past? What if the angels are not mythical beings, but just a civilization so far higher developed than ours, that all they do and create seems like the works of gods? What if Atlantis really existed but on another planet?
The idea that Atlantis was on another planet and an old human civilization was inspired by the Stargate Atlantis series, in which a similar scenario exists.
The idea behind the
Pink Mist was inspired by the Chaos of the Warhammer universes. Same as the
War in Heaven.