For most of the Korean fighting action/revenge movies they are put together well and the story flows. In this one it's difficult to get fully immersed in the action as the dialogue scenes aren't really well written.
Mostly it drags, but the action is good, camera work is well above but it has tons of things that could be done much better.
Lots of scenes dedicated to secondary characters, but they don't seem to fit and are just basically filler. There could have been tons of more scenes written to enhance the overall film.
I started at 5 stars, went to 7 after the first 20 mins, then back down to 4-5 for most of the movie. The ending is utterly atrocious and this film would really be much better with a few edits to the writing and script. 1/10 for the ending, yes that bad for an action movie. Overall 5/10 tops.