The first part of the film was good and most of the time the sequels are disappointing, but in this case it's better.
The story line is very well done and as I expected the second paragon (Kim Soo Hong) is definitely more intelligent and interesting. I like the way he approached his trial, the actions and questions he asked to push the guard Kang Rim to free himself from his past throughout their journey. And Joo Ji Hoon as Hae Won Maek is refreshing, I like the duality between the warrior and the man even 1000 years later. I didn't know Kim Hyang Gi as an actress but she is stunning as Lee Deok Choon, she is the face of innocence with a tigress inside her.
I will also add that the CGI is very well done, it feels so good to my eyes, the fight scenes are very well orchestrated, Goreyo here I come.
At the end, I had my answer on who these guardians were and considering their links the 3rd and 4th part of this movie will have to be epic.
If I had to describe this film: the path to redemption (without religious connotations)