This feels weirdly like the game Morrowind. Not that I have a problem with that (it is my favorite game in the entire world), but the ash storms and the slavery and the mentions of Great Houses ruling under an empire? A religious Ministry that appears to be based in a city divided into cantons? Yeah, seeing a lot of similarities. I'm enjoying it so far, and think this might properly "stick" and I'm likely to finish it, which I have been having some trouble with lately.
Plus it is the first book in (at least?) a trilogy, and this guy seems to pump out books like nobody's business. Wow. I'm not sure what to make of that.