This is how you do a Korean historical drama. Hella raw, tight, tense, packed, epic. Certainly pales in comparison to the run of the mill historical drama that Korea churns out. This feels real. This is captivating. I can root for the main character, I am right behind her. I do not feel cheated out of my time by countless hours of fluff. So it's safe to say it's the best I have seen so far. I haven't tried that many, but what I did watch left me with a distaste for the genre. I generally avoid them.
Admittedly I got into this for Ji Chang-wook and it is such a nice departure from the other k-dramas that he's done. I haven't seen his action thriller ones, just his rom-coms, but man he actually gets to act here. I knew he could do it but I have seen none of his mannerisms from the other ones. It's a completely new arsenal. They certainly worked on his face and physique and well, basically for me it's the most real character that he's played and I realize this is a fantasy historical drama, but still.
This is not the Queen Woo I initially thought of, no relation to the Chinese Woo of course. She is said to be fictional, but I hope there have been several Woos out there in Asia. I can totally see it. I liked the actress, she has a very commanding presence in all her scenes, I am surprised her filmography is not that large.
The pacing is very tight, so much is happening that you can barely keep up, there are so many factions and players exposed that you can hardly distinguish between them, I gave up at some point and tried to enjoy it as it unfolded. It uses flashbacks a bit too much to give historical background and to elaborate on various characters' past. It's not a concern, again I took it as it came. There are a lot of narrative threads and it seems to end with a clear hint at a second season, so that will probably happen.