I don’t remember where, but I heard that Warbreaker was one of the worst Cosmere novels. And after reading it? I must respectfully disagree.

Warbreaker stars two princesses of the kingdom of Idris, Siri and Vivenna. When Siri is sent to marry the God King, leader of Hallandren, in Vivenna’s stead, she finds herself in an unfamiliar land of gods and colors. Fearing for her sister’s safety, Vivenna follows after her, only to find herself embroiled in a plot to cripple the Hallandren war machine. All the while, Lightsong, one of the gods of the court, begins to see ominous dreams of war. And the mysterious Vasher, along with the talking sword Nightblood, leave a trail of bodies in their wake as they pursue a mysterious purpose. As tensions rise and war slowly becomes more inevitable, can any of our heroes find a way to prevent it?
This is an odd book. The beginning isn’t particularly strong (save an excellent prologue) and the ending is rushed and unsatisfying. But everything in-between is pretty good! Far from perfect, but enjoyable!
Reading this after reading all of the Stormlight Archive books felt like someone was turning on lights in my head. The answers to more than a few Cosmere-related mysteries within those books can be found here. It doesn’t do much to improve the quality of this book in particular, but it did add a layer of fun as a Stormlight fan to pick up on all the stuff that appears in those books.
Character wise, this book is pretty strong. Its cast isn’t especially complex, but they’re all fairly memorable. Vivenna had a great arc, going from a condescending stuck-up princess to a level-headed and non-judgmental badass in the making. Siri goes from a free-spirited little girl to a confident young ruler. Lightsong goes from a lazy, apathetic god to a heroic savior. Simple arcs, but satisfying ones.
However, the dialogue often leaves something to be desired. If anyone other than Lightsong or Nightblood opened their mouths, I quickly found myself removed from the story. It’s either repetitive, driving the same information we’ve received over and over into our skulls like a hammer hitting a nail, or it just comes across as stiff and awkward. Denth and his constant “You know what I hate most about being a mercenary?” lines got old really quickly, but they just kept coming!
As for the worldbuilding, this book is… fine. Nothing especially memorable or interesting, but nothing terrible. It’s a decent fantasy setting, but not one you’ll remember like Middle-Earth or Westeros or Roshar.
I do, however, love the magic system. Breath and Awakening is such a simple and cool power and it’s used in really fun and creative ways in this book. I only wish we got more of it! There are all of two characters in this entire book who actually use Awakening. I wanted to see some cool Awakening duels!
The central mystery of the plot is another thing I really like. It isn’t the most incredible mystery I’ve ever read, but it’s certainly well done. The twists are shocking in the moment, but make perfect sense when you reflect on them. There are plenty of clues sprinkled throughout the story to help you piece it all together. It won’t give Agatha Christie a run for her money, but it services the story very well.
Overall, I think Warbreaker is a decent book. Not absolutely phenomenal, but far from the worst book I’ve ever read. If you’re a Cosmere fan, this one is definitely worth checking out. If only to figure out where some of the extra crazy stuff in Stormlight comes from.