This is our last review of a Cradle book, at least for awhile, since there aren't any more currently written. However, this is by no means the last book in the series, so I sincerely hope that Will Wight will be returning to finish the series soon. As amusing as it would be to be able to say that I read this book both first and last in the series, that mild amusement would not come close to balancing out the disappointment of not being able to find out how the series ultimately ends.
I came off of reading Ghostwater especially eager for this sequel, Underlord. Ghostwater provided a substantial amount of imaginative information about the deeper intricacies of the magic system, and I was hopeful that Underlord would give us the chance to see that new knowledge applied. Instead, Underlord gave us insight in an entirely different direction, involving the characters (and by extension us) in the fringes of world-wide political intrigue.
Unsouled, and the Cradle series as a whole, is described as something called martial arts fantasy. The magic system has defined levels of skill, with each skill level gaining distinct abilities and possessing unique attributes. It's not a design that I generally prefer, but it worked well in Unsouled. Which matters, because Unsouled is not necessarily the kind of book that you read for the compelling characters or political drama. You read it for the vivid magical fights.