So, having left it alone for a couple of years, I finally got around to returning to the Codex Alera, specifically, Book 4: Captain's Fury.
I think what I enjoy about Butcher's style is he isn't afraid to let his heroes be as smart as his villains, which really makes the conflicts interesting, as move gets met by counter-move. Though in this one, there is a stunningly brutal final move from Gaius. Taking out your enemy by siccing a sentient super-volcano on them and the inhabitants of their entire city is certainly a new one and it certainly ripped Kalarus a new one. Was he right? Even Gaius presents it as a lesser evil option to reduce the overall death toll, even he knows it can't be spun as anything good. Arnos also makes for a quite awfully oiley snake of an adversary and there's no shortage of Arnos' in real life.
All in all, this feels like the conclusion of the middle act, with the Canim and Kalarus plotlines mostly concluded, so time to start on the two-book finale.