This is a supernatural fantasy, with the slight difference that the devil is actually some person who died, got converted to a demon, and presumably killed off the previous devil. Not that that is important. It appears from the start that the devil is sending a demon army to conquer the major city and kill the king. For that, we follow some major demons. Additionally, there are Death Gods, a Brotherhood, and various other groups, most of whom seem to be evil oriented, but unlike some stories, the demons have limits on what they can do, and the better guys do have some tricks. The better guys, of course, have to defend the city and keep the king alive, or do they really? There are a number of games the better guys are also playing while dealing with demons.
The writing is clear, and the world-building is superb. Some parts of the story may seem a bit odd at first, thus the devil sends a demon to do a very important job, but said demon is blind. Think about that! Author Glicksman has put a huge effort into this story. The characters are plausible in their behaviour and the story is a lot more than simple violence, of which there is actually not much. As for the forgotten Queen, she does not become apparent until nearly the end of the story, but . . . This was great, except for two points, which for me cost a star, but maybe not for you. The first is there is a huge cast of characters, and leaving aside allegiance difficulties, sometimes I had trouble remembering which group they belonged to. You expect unusual names, but just maybe for formal purposes names could be oriented just a little more to give clues as to what they are? The second was that each character seemed to have an extensive backstory that had to be introduced. For me, this slowed the story, but if you like everything to be laid out so that you know all of what is involved to that point, this will be a great story for you.