This show started off boring, let me warn you. The only reason I kept watching was for Lee Soo Hyuk. Man! That guy makes evil look hot! All the blood dripping from him could never take away from his attraction. The way he moved, smirked and especially the pitch of his voice made me melt every time he was on screen. You can't divert your attention from him. I started this drama loving him (even his character too) and ended it still cheering for Gwi. What Lee Soo Hyuk does for Gwi is sinful... because all the viewers fell in love with him and totally forgot about the main leads' story. I watched on Viki; all the comments are proof. Lee Soo Hyuk stole this show. So now that the fangirling is over.... This story starts pretty boring. However, by episode 6, things start to pick up and by episode 8, it gets really interesting. However, there were moments it dragged and I skipped scenes looking for Gwi who is the most interesting, and smartest character in the show. His intelligence compared to the other characters would blow you away. After the story picked up, things went well. I liked Lee Joon Ki - his portrayal is good as always. However, there were some moments I found myself thinking he should take vampire lessons from Gwi. Acting lessons too - which is strange and taboo because he is a veteran actor! Also, his romance with Lee Yu Bi is flat. The viewer never really cares what happens in that romance. They keep watching for the outcome of the mission. Also, a bone to pick with the writers - Lee Yu Bi's character is pretty smart,, outgoing, and fearless when she is dressed as a male. However, put her in female clothing and her intelligence and bravery hits -5. Not even 0, but -5. Why is that? What are they trying to imply? Given that, Lee Yu Bi's character turned out pretty lacklustre and you forget to care what happens to her. Sad when you don't care for your main leads much and cheer for the villain through all 20 episodes. The acting by all the leads and supporting cast were awesome. They all carried their characters well. Shin Chang Min took about 3 episodes to really get the acting straightened out, and Lee Joon Ki's vampire was laughable in the beginning, but they got waay better by episode 10. Only thing - those baring teeth by Lee Joon Gi was boring. He could never do it as smooth or believable as Gwi. Plus, this was his only vampire mode. I mean...really? I also loved Kim So Eun's and Jang Hee Jin's characters. Sure, there was a time in the beginning I didn't like Soo Hyang, but she develops nicely. Hye Ryung too. Their character developments were well done. Sung Yeol and Yang Sun's characters did not develop but remained flat. Maybe that way why the romance fell flat. That and the lack of chemistry. However, their acting were perfect. The script's characters were the problem. I would not rewatch because... read the above. The story was pretty boring. I just watched for all the actors. This story would fail as a book. The music... was laughable. In the first few episodes, I was hoping they would fire the music consultant. Happy music in killing scenes, up-beat tones for sadness etc. You'd go crazy, so go with care. I think they changed the consultant though, because it does get better at around ep 7. I would advise to watch this for the actors and the scenery. If you can pull through the first 5 episodes, you might like the story. I watched for Gwi so I regret nothing. I'm a lifelong fan of His Prettiness Lee Soo Hyuk now. He makes evil look so hot for 20 episodes. I never lost my zeal for Gwi because of his amazing portrayal.