I believe it’s pretty decent, earning around a 7 out of 10 from me. What bothered me was something that appears to be a cultural tendency—a habit of elevating certain figures. In this show, for instance, there are five or eight characters who are portrayed as being exceptionally powerful; one, in particular, is presented almost like a deity—invincible, capable of defeating anyone, and completely unique, similar to Chuck Norris. This unfortunately detracts from the believability of the series and seems geared toward a younger audience that might look up to figures like Chuck Norris or Rambo. I've observed this pattern in other Korean television programs too. Aside from that, it was enjoyable.

Source on TMDB