I really liked this series, though I have to admit I liked the first two thirds or so better than the last third. There is a shift in focus towards the end, from focussing on the two leads, their personalities and love story, to a huge problem they encounter and how to deal with it. It is more sad towards the end and more frustrating because you just want them to heal and be happy.
Besides that, I think another problem with this series is that many probably started out watching it believing it was some sort of superhero series, which it is definitely not. It is instead a very interesting take on the effects of abuse and heartbreak. Someone who has gone through these things might desperately want to love and trust again, feel very lonely and angry, but when they finally open up and get close to someone, they get so scared of being hurt again that they can't help but push the person they want to be close with away, hurting them in the process. It's like they turn into a hedgehog that rolls up with the spikes out in order to protect themselves from further emotional pain, disappointment and heartbreak, however the isolation and loneliness and causing the other person pain is just as unbearable. So that's exactly what the blades represent, they are a physical manifestation of what's going on inside the person who has these issues. It is therefore a very emotional series, but not at all a superhero series.
I particularly liked the two leads. Unlike in other series where just one of them is likeable or the whole story only works bc of the strong attractiveness of the leads, these two leads' are both very likeable and you kind of look deep into their souls. The male lead is a horrible person at first with obvious severe anger and personality issues, abusing and mistreating others all the time, but over the course of the series it gets more and more understandable why he turned out to be this way and as the relationship with the female lead develops there is a huge character development in the male lead, which is very beautiful to watch. Also the child involved in this and the relationships built with the child are very touching and sweet. It is just very heartwarming and I'm still impressed how Lee Dong Wook pulled it off to portray a character so unlikeable and horrible at first, but you can't help but also find him sweet and likeable at the same time and really care for him and want him to get better and happy again. Also impressed by the female lead portraying this very wonderful woman. I think she was the most likeable female lead I have ever watched in K dramas, just a wonderful person in every possible way. Also as many have said before, absolutely loved bodyguard Ko and many other side characters.
So all this to say, there are flaws in this series, the shift of focus towards the end, the misleading poster that makes it look like a superhero movie... But the beautiful things outweigh these by far and it so overall it is absolutely worth watching and I highly recommend it.
