The is your typical story about one's journey for vengeance that derives from the death of their loved one. There were some highlights, but also elements that downplayed the drama. Although this is a relatively short K-drama than the norm, it did serve some really cool fight scenes and top-notch acting.

Knowingly, the biggest factor that downplayed this drama was the fact that it was too short. The overall flow of the drama story and how it progressed was excellent, considering there were only 8 episodes and each lasting around 50 minutes. However, that left with a very anti-climatic ending that felt rushed. I also felt that it did not give a conclusive ending to the main character which I am guessing was up for open interpretation. Thus, whilst I enjoyed seeing the story unravel, the ending diminished the fact that this drama would have made it into my top favourites list.
Unlike a normal 16 episode drama, this show had a very minuscule time to build the backstory to the characters and enable other things to develop like the tiny fraction of romance that took place which added no value to the story at all, but I suppose gave meaning to the parties involved. Particularly speaking, Jiwoo and her Dad's story, together and apart, lacked depth in terms of the events that took place with the Dad and the breakdown of his relationship with his family.
This drama is predictable for the most part, but there were some elements that took the viewers by surprise.

Besides this, I would have to give credit to the acting. Jang Yool as Do Gangjae was pulled off impeccably with his intimidating and villainy demeanor. Han So Hee as Jiwoo/Hye-Jin was remarkable and immaculate. Her display of various emotions throughout the drama was truly amazing.
I liked how the writers gave us an open interpretation between certain characters and their questioning relationship which makes it for a rather juicy debate and discussion; delving into the hidden emotions behind them

This would be a good drama to binge on if you are looking for something short and do not have too much time to invest in a normal K-drama, but be mindful, if you are looking for a conclusive ending, then this may not be for you. Do be mindful that there is a lot of violence and disturbing scenes.
Generally speaking, I do not usually watch action K-dramas, I am not sure why, but this drama now propels me to hop onto the bandwagon of action dramas and move away from my usual watch preferences.