Well, I didn't like it as much as everyone else. After a while, I just wanted it to end, as I could pinpoint the true by eps 9. Too unrealistic the way one guy can fight 20 holding bats, knifes, etc and still win. In real life no one waits a mano-a-mano fight, he would quickly be overwhelmed. Still! I like the main theme and the acting are really something here. It was fun at first.
The longest kdrama I've watched. It has some ups and downs and it's pretty clear how they rushed this series on the last episodes. While I can understand Hodong character, I could never sympathize with him so I didn't care for his love life (or lack of it). But there were some amazing characters here like Lady Mo, general Wang Hol [*faints] and king Choi Ri. Let's not forget the queen of poisons mrs Wang Jasil - even though the majority of time she would fail and the poison didn't kill its victim.
However I must complain how the first episode spoils so much. It even tells us who is dead. Bad move, guys =/
Wow, a lot of good comments. Too bad I couldn't enjoy this drama like everyone else. I thought it was a bit silly and boring, I fell asleep a lot of times while watching it. Well not my cup of tea for sure.
K-Drama 
Still! I like the main theme and the acting are really something here. It was fun at first.
However I must complain how the first episode spoils so much. It even tells us who is dead. Bad move, guys =/