A lot of plot twists that keeps you at the edge of your seat. With a cast that consists of one of the best villains I have ever seen in a k-drama, a male protagonist that hits you in all the right spots, a female protagonist that is naïve and clueless just the right amount and a supporting cast that just brings it all around.
Kudos for the production and visual effects team that made this full of fun car chases, explosions and all around bad-assery in high quality. The OST gave it the romance feel that sometimes you just felt you needed, which brings me to another really good point, which is the very good balance between all of the punches and politics and estrategies with the much needed romance. The protagonist's chemistry was to die for, but this one has some excellent writing and you will find yourself getting teary by the fact that the villain didn't get her way. Haha.