A creative premise that was well thought-out and has aged relatively well in terms of production and presentation. The show blurred the lines of reality, blurred the lines of good and evil, and ventured into concepts that were waiting to be explored.

BUT.

Sometime after establishing the, uh, logistics and rules of the universe the show decides to flip the script and break all of its own conventions. At first it was just minor details that were occasionally to mildly annoying. Then you notice inconsistencies, Then the story develops too many ideas without knowing how to finish them. The twists and turns throughout and effort to commit to things that are not usually done/done well in the k-drama world does deserve credit.

But effort isn't everything. You still have to know how to execute and have an idea of how things should play out. Unfortunately, the show began to lose itself in its own proverbial plot. And that friends, is not exactly a W.