Ehh, The Salvation War has some interesting moments about facing down existential threats and not giving up and building a bright future for humanity across the corpses of eldritch horrors, but you have to be willing to slog through a lot of drek. I read the first book of The Salvation War and it can't seem to make up its mind just to what extent it's supposed to be following any particular cosmology, mythology, or theology. I get the impression that it wants to be a chronicle of the moment when humanity cast down the Hordes of Hell, but it's executed more like a chronicle of the moment when humanity engaged in massive amounts of gun porn against acid-blooded fire-spitting lightning-throwing ogres, that happened to be called demons. I say ogres because they're large, brutish, stupid, and generally fill much the same niche as ogres do in Dungeons&Dragons. Whereas many of the classical demonic attributes like temptation, seduction, offering forbidden knowledge, reading the hearts of men to know your dark secrets and embarassing desires, or confronting you with a litany of your sins, have been left more or less by the wayside.