Fantastic pulp; if you skip over the long graphic descriptions of the consensual non consent fantasy of women willfully surrendering to hulking monsters, which to be honest did get a little old after a while, you're left with a world war z style anthology of the destruction of a nation populated by a couple of characters you actually want to root for. A debauched empire being overrun by sexually aggressive evil creatures in a quest for vengeance against humanity? Kind of an interesting premise.