I must admit, I was taken aback that Netflix created this show; it’s unlike anything else they usually put out. "Mercy for None" is a raw, South Korean crime drama—but amplified considerably. It's packed with non-stop action sequences and an apparently limitless number of skillfully staged fights, presented in a brutal fashion by a central figure who appears to be invincible. As is common with Korean series, the writing is smart, featuring a fairly intricate background story and memorable characters whose reasons for acting are frequently understated and occasionally fatalistic. It’s not simply about physical strength; there's much more than that present. The one area where this show falters somewhat is in the level of violence displayed. Some scenes are intensely graphic and could perhaps have been toned down a bit. Overall, it’s an excellent series for those who enjoy dark, realistic crime stories with a harsh, uncompromising tone. It's absolutely worth watching.

Source on TMDB