The premise of this drama is super interesting. I loved they decided to go for a very dark tone to explore the vigilante concept. I was positively surprised how far they went into the violence and the choices made by the "hero". The introduction of the story hooked me but I was unfortunately very disappointed by the pace and the writing overall. It felt strangely slow and not as gripping as I would have wished.

The writing did not convinced me. Maybe it is because the series was too short but I found the side characters lacking development and the way the events unfolded felt rather predictable. The hero was a bit too omniscient but without enough details to support the fact he was so ahead most of the time. Some of the relationships he built along the way were pretty compelling but would have benefited from much more screentime to make their bonds believable.

The casting is pretty good overall. I was really impressed by the performance of Nam Joo Hyuk: he was really frightening in Vigilante mode...His gaze shifting from his "regular" persona at the police academy to his vigilante mode was amazing. I also appreciated a lot the other male main roles: Yoo Ji Tae and Lee Joon Hyuk. All three are excellent, even when I felt the scenario give them not enough to work with, they somewhat gave it their all. Unfortunately, I really disliked the sole female character of the series, played by Kim So Jin. I am not sure who is the most at fault here: the screenwriter or the actress, but clearly that character was horrendous.

The production value of the series is high. There are a lot of well-executed fighting scenes. It is very comics-like with the good guys being outnumbered by the villains but still making it through...and those sequences are very enjoyable to follow. The soundtrack was okay but not memorable to me.

I would not recommend this to people unless you like one of the main actors or the source material (which I have not read). The idea is good but the writing does not support it properly and the pacing felt oddly sluggish given the low number of episodes. Though if you are a fan of Nam Joo Hyuk, you need to watch this drama because he is brilliant in it. Be mindful if you have any trigger, it is very violent.