Ryu Si oh carried the whole show, and ofc they killed him. I've seen many kdramas and series in general where one of the most important characters, either protagonist or antagonist/villain was killed, but this did not ruin the show. Neither gave us the impression of a bad ending. But this? Totally unreasonable and bad choice. His death dropped the rating for most of us from 10/10 to barely 1/10.
