As a person who's been a K-Drama fan for over a decade I'm telling you from my experience that don't ask me any questions and just go and watch the drama. I mean it when I say that this drama is perfect and awesome. This drama is just so awesome.
The drama is high on action, like every episode has multiple action scenes. As the show is yet to finish I'm highly anticipating how it'll end. The drama doesn't have any unnecessary romance scenes unlike many. I feel like that the creators were highly aware of what should be there and what shouldn't cause it's very evident with the end product.
Be it be the casting, VFX, OST, acting, story or anything this drama is just perfect. I really wish for a happy ending but the title has the beginning in it so maybe like maybe there will a season 2? Who knows???