I just finished it and I will make it short—the story, the fighting scenes, the soundtrack, the visual effects, and especially the acting: Everything is perfect. There must be a season 2. The storyline has so much potential and they didn't waste it. The drama ends where the original webtoon starts. I really really hope there will be a season 2.
Park Ji Hoon is remarkable. The perfect casting, he is on point in delivering this character, and so is the rest of the cast. But he really outstanding. The fighting scenes never get boring and you root for him in every single one. I've read that some of the production team members are also involved in D.P. which is also one of my all-time favorites, I especially felt it in the overall vibe. Even tho the topic is serious, brutal, and heavy there is also something comforting about the show (like it was with D.P.). The intro was also wonderful and is a no-skip. I can really recommend the drama, especially if you like revenge storylines. This show has one of the most satisfying revenge storylines I have ever seen. 11/10. Perfect.