I was hesitant to watch this because of all the scandal surrounding the drama, and the low rating on MDL.
I also had never seen the ML in anything before, and was not familiar with him as I was Ji Soo, who was originally the lead and was replaced. Na In Woo was amazing as On Dal, I couldn't imagine anyone else in this role. He was great as the bumbling fool, and equally as captivating as the serious General On. His chemistry with Kim So Hyun was also incredible to watch and had many swoony moments. I also loved the supporting roles in this, although at time it felt like there were too many side stories going on. It was hard to root for the side couples toxic relationship, that story captivated me the least. The big drawback for this drama was that it did feel like some episodes were unnecessary. It also felt a bit clunky, and obvious in the episodes where they transitioned to the new ML, episodes 7-8. I feel though that they probably did their best given the situation. Please give this a chance, it's a beautiful love story with tons of action, but go in with low expectations like I did and you will be more than surprised.