The drama had one of the best cinematography, grip worthy plot and intriguing action scenes. But it's not for everyone. You must have immense patience to appreciate the storyline and the direction. Many a times it might even feel a little dark. But that's just the genre of this drama.

Story:
The story was quite great. It's unique and thrilling. Almost every character was beautifully written. The assassin's training sessions and the development of the story was all new. Most importantly, I loved the action scenes. They were so smooth and so well captured. Even the females were given great scenes. The only thing that was difficult for me to absorb is the constant fight between the assassin's conscience and the action of killing, especially in the case of the leads. In the name of survival, killing is promoted. Usually for an assassin, there is no conscience. He either works for money or for revenge. These 2 reasons are digestible. But the excuse of personal survival is too negative for me. There are many ways to survive. Therefore, at many points of the drama, I felt angry at the characters.
The storyline is indeed deep and heavy. So watch patiently.

Cinematography:
Absolutely fantastic. Every set location was unique and beautiful. The costumes were gorgeous. I believe the only thing restricting this drama from going into the category of 'dark drama', is the visuals. At various points, the visuals were lighting up my mood.

Acting:
Acting was good. Everyone played their part beautifully. The chemistry between the leads was obvious from the first time they met. Their story was emotional. Again, the only annoying part was the 'conscience v/s killing' scenes.

Conclusion: Unique story, thrilling storyline, amazing visuals but a little dark. This is why I labelled it as 'A Good Artwork' instead of 'A Good Drama'. I won't be re-watching this show. Even though I highly appreciate it but still, one time was enough for me.