I started watching this drama because I LOVED LJK in Scarlet Heart Ryeo, and all the visuals, (LJK, Changmin and Lee Soo Hyuk) were too good to pass.
(SPOILERS AHEAD)

Storyline : 7.5

Majority of the drama is very interesting and makes me anticipate every moment. It makes me wonder what the 'secret plan' to kill Gwi is and how Gwi is gonna die. Also that ***** Prime Minister who is trying to usurp the throne, I always wonder what is up his sleeves again. The first 3/4 of the drama is also executed very smoothly and everything falls into place, however, i feel that the ending is too rushed. The way Gwi actually was killed was mainly helped by explosives which is a rather anti-climatic way. Also I was seriously hoping to have some of Gwi's back story, I wanted to know how he actually came to life. AND HIS LOVER, he said that he fell in love with a women before, yet, it didnt have a nice emotional flashback as I expected. I also feel that the ending is lacklustre as it felt rather rushed.

Acting : 8
LJK never disappoints, the way he expresses himself and shows his inner conflict is well execeuted! Lee Soo Hyuk too! His acting as Gwi is extremely realistic + he is really good looking :) Kudos to Changmin too, I think he did a good job playing the Prince (later the King) showing his struggles (he is an idol actor so I didnt expect much but he exceeded my expectations). The Female Lead was good too!

Music : 8.5
Not really a person who takes note of the music but I think it was fitting when played.

Rewatch Value : 4
Not because it is a bad drama, its just a drama that is hard to rewatch as the audience already knows the plot and ending, the romance part is rather little too

OVERALL : 7