In Sins of Empire, Brian Mclellan brings his unique magic system to the fore. His brilliant blend of sorcerous Privileged magic, bone and blood magic, and almost-telepathic destructive Powder Mage magic is just stunning. Magic systems simply do not get better than this. This is full blown all-action magic, simply brilliant.
I must credit the author here for the writing. The language and the expressions is vivid and precise, lending the perfect amount of realism to the literary imaginative of the books. That is, the writing is such that it makes for easy, vivid and stunningly real picturing of events in one's head.
Events leading up to the climax are just as engrossing as the climax itself. That the author managed to create such unforgettable characters in just a few pages is a testament to the beauty of this book.
While the author uses typical fantasy themes, there's a couple of new elements, elements usually found in such genres as Thriller/Suspense and Detective stories. In fact, the story is a strong blend of themes from fantasy and normal modern fiction. The exploits of Gregious Tampo, the Ice Baron and Michel Bravis bring to mind some of the more fast paced Thriller reads.
The world building is quite good, for a book that doesn't focus so much on setting. In a nutshell, the book depicts a struggle for power between good, gray and evil characters, set in a world similar to 17th and 18th century Europe, and featuring more than one unique set of magic systems, with enough action to rival a Bond film, and unforgettable characters.