The storyline is quite weird, but the tone is fast, intriguing, and makes the drama addictive.

Sure, there are a lot of story holes, a lot of unanswered questions, but that's the game in this type of series.

The actors are awesome (I really like Sky Li in everything he plays) and the (essential) special effects are neat and convincing.
The OSTs are excellent and effectively accompany the different atmospheres.

I won't talk about the story (everyone has read the synopsys), I'll just strongly recommend this drama (short - only 12 episodes of 35 minutes) and exciting!