The House War series is one of three co-existing (to some extent, each of the series co-exists in time, often with the same characters) series written in the same universe by Michelle West, a half-Japanese, half-Canadian writer who first came to my attention when I was stunned by the first book of the Sun Sword series.
The universe created in the three series (the Sacred Hunt duology, the Sun Sword series, and the House War series) extend across over thirty years of time in-series and involve as many varied perspectives, people, and desires as the more infamous large-scale high fantasy book series out there (the Wheel of Time, the Game of Thrones, The Malazan Book of the Fallen, etc). However, it is distinct in every way from them in style.
While the world West puts together is often as harsh or more so than the Game of Thrones series, it manages a degree of mystique that Martin never achieves, at least partly because the focus is more on the people and setting then making as many dirty deeds as possible occur in the shortest time possible (incidentally, that is my assessment of Martin's works). A typically Japanese flavor exists in the writing, mixed with flavors of Celtic and even Middle Eastern tones at times. Depending on which characters form the core of an individual book, the atmosphere differs dramatically.
The House War series is centered around Jewel Markess ATerafin and the people that surround her. Jewel is a key character in all three series, though in different ways. In the Sacred Hunt, she is the desperate leader of a den (think street gang) of orphans whose existences are only considered relevant relative to her. As such, little focus or spotlight is put on the den, except to give them some minimal color and give you a vague idea of how they matter to Jewel. Jewel is seer-born, a rare form of 'talent' that causes her to see potential futures in dreams and instinctively (knee-jerk, gut-level) know when her own life is in danger and avoid it reflexively. Other talents, such as mage-born, healer-born, god-born, bard-born, and maker-born are all present in the series, but explanations for each are generally only presented as aspects of their existence become relevant to the story at large.
She lives in Averaalan, the capital city of an Empire ruled by the Kings, two god-born children born of the gods of Wisdom and Justice. The complex society of the Empire nonetheless has only a very limited privileged class, made up of a wealthy but not feudal 'patrician' nobility, the commons, and the Ten. The Ten are one of the constructs I like most, besides the Kings, in this particular setting. They are a group of ten aristocratic clans that are granted almost complete internal autonomy and are not hereditary. Instead, the Ten increase their numbers by merit-based adoption, wherein individuals that have talents and skills desired or needed by the clan as a whole are 'adopted' regardless of origin.
The House War series follows Jewel's life from early childhood, details the creation of her den, and further writes in details of the events around the duology solely from the point of view of the den and Jewel herself in the first book. The rest of the books detail her rise after the events of the Sun Sword series to the rank of the Terafin (the ruler of the Terefin, the greatest of the Ten) and the results of her choices until she meets her destiny. Of the three series, the House War series most deeply details the aspects that are left oblique and unexplained in the previous books, regarding the nature of human talent-born, the nature of power in that universe, and the nature of the immortals and gods.
Jewel is, other than her power, merely a fiercely compassionate woman who cares far too deeply for someone who rules. Her immortal companions are frequently frustrated by her (mostly because they only understand the power she wields and what it will become), and her mortal companions fear for her as her power grows and she struggles against the necessity to change in order to master it.
The over-arching antagonist of all three series is Allasakar, the Lord of the Hells, a being that is deliberately demonized (lol) in the Sacred Hunt, given some perspective through the eyes of Kiriel, his half-human daughter, in the Sun Sword, and given a third and more complete relative perspective based on the truths revealed in the House War series. I won't go into detail about this, but Allasakar is presented as being inimical to all mortal life... and this is true in every way. However, one thing that gets revealed in a rather stark manner in the House War is just how inimical ALL immortals in this series are to mortals.
The world Jewel and the other characters live in is one that is asleep, the gods having withdrawn to another realm for reasons of their own, the Firstborn (their 'children) confined to the mystic wilds, and many of the other immortal existences in a thousands of years long sleep. Because of this, a marked difference between the early books and the later ones is the stripping away of the gentle human 'myths' that gloss over just how terrible the immortals, regardless of alignment, were.
If the Duology was a simple good vs evil play and the Sun Sword was an interwoven tapestry of demons an politics, the House War is the mortal coming into contact with and struggling against the immortal. Michelle West's concepts of the immortal are very Japanese, for someone familiar with Japanese Buddhism and Shinto. Indeed, I can say that while there is a strong Celtic influence on the aesthetic, the essence is almost entirely Japanese when it comes to immortals in the story (it becomes even more so later on).
For those with an interest on why I said there is a strong Middle-eastern influence, I recommend you read the Sun Sword series. Following the events in the lands of the Dominion, in particular the first book of the series which almost exclusively centers around that region with few outside influences, brings that influence out in full. Serra Diora, one of my favorite characters in the series, is someone I can honestly describe as one of the most admirable characters in the series as a whole, while being one of the weakest relatively (Edit: In terms of power, not personality). It gave me a much better perspective on Middle Eastern culture, and it is one of the reasons I actually began reading some literature from that part of the world.