I kept going back and forth between 3 and 4. The first season was definitely better than the second, but I loved getting answers in the second season. For me, the worst part in the second season was the dubbing. I felt I was listening to terrible anime dubbing paired with strong lead actors.
Of course, Min Hye-jin was my favorite! Totally bad ass, brilliant and beautiful! The storyline/plot was actually great to me. Very believable because this is a true battle. Church and State.
Overall, I definitely enjoyed. Will there be a third season? I hope so!