This series seems to follow a pattern for me: I thoroughly enjoy each book, but they all have one major issue and one small issue. But still... I enjoyed this one just as much as the others, and I'm incredibly happy that it hasn't fallen off like so many other authors do after a few books into a series. Rogan has kept consistency in quality and characters, but more importantly for me is consistency in story and worldbuilding.
My main complaint in the last book is that Ryn was an underwhelming leader, flip flopping between being strong and decisive and needing his auxiliaries to carry him. That's still true in this book, but it's not as severe. I'd definitely like to see Ryn carry a fight on his own without his auxiliaries having to save his butt; something to justify his role as primal conjurer and the special treatment/authority he's been given. A primal conjurer is supposed to be the most powerful of mages... so show us.
So my main issue with this volume is characters having a major case of The Big Dumb. After discovering several devil-marked at Clarion Flight Academy, the assumption is that there's likely more. Definitely a safe assumption. The issue is that they have no clue who it is, but they blindly trust someone to the point where Ryn happily locks himself in a room alone with them and the auxiliaries - whose main role is to protect him - raise absolutely no concerns except for Nephale going specifically to keep an eye on the devil-marked they know about. No one's suspicious, no one suspects, no one even remotely considers the possibility despite their experiences (especially Nephale). So when the inevitable happens it's not a big reveal or a shock... just a big facepalm moment.
My smaller issue is that one of the devil-marked gets off pretty easy. I completely understand the in-universe justification for it, but it just seems really weak and convenient because she's a LI. Or will be.
Still, as with the other books, the summary stays the same: aside from the above, the book is still fun, engaging, the characters are still there, and I thoroughly enjoyed it. One thing of note is that the party doesn't actually reach the Academy until 70% of the way through the book and everything happens pretty fast from that point. The rest of it is the journey there. That's not a negative for me, but like the slice-of-life nature of the first book it should probably be mentioned.