Promise of Blood is what is known as "Flintlock Fantasy" which means it contains a world where guns (musket/flintlock era weapons) exist alongside swords and sorcery. This book introduces the concept of Powder Mages, who are gun using sorcerers that rely on gunpowder to fuel their abilities. Powder Mages are able to enter a powder trance by ingesting gun powder which allows them to manipulate and control bullets as they fly, or even explode nearby gun powder being carried by their enemies. It is a unique magic system and executed pretty well by Brian McClellan. That concept, combined with an interesting story arc, carries the series and make up for the characters which I found to be a little uninteresting as a whole.

Mistborn is an excellent series and I thoroughly enjoyed every book in the original trilogy: The Final Empire, The Well of Ascension, and The Hero of Ages. I was completely drawn into Sanderson's world of Allomancers and all of the interesting things they could do right from the start. For the uninitiated, Allomancy is the art of "burning" an ingested metal to enhance your own physical and mental abilities. One of these metals let you mentally push yourself off of nearby metal objects and another lets you pull the metal towards you. With each metal having a unique ability Sanderson is able to create a society where Allomantic powers are used in very creative ways and the magic system alone makes this series a win. There are 8 metals that can be ingested/burned and most Allomancers can only burn a single one; however, there are rare individuals who can burn all 8 and these are known as Mistborn. All 8 powers in one person - that's when things get really interesting.