It was a very good drama. Unless for personal grudges with the actors and actresses, there's nothing much to hate on in this drama

My favorite part in the story was how the writer presented the logic of vampires being infected by a virus and how that concept was religiously maintained throughout the drama that alone is gold point for the script writer.

I'm very much vexed at the finale, it almost or did rubbish the entire story. The writer ought to have calmed down and developed a breathtaking ending since he really did a good job with whole thing until the finale. The last part might have you ramming your head to the ground in frustration but a good drama nevertheless. I recommend a watch because you can't say no to seeing a kdrama at least once?