Good premise, good story, GOOD ACTORS, not bad acting. But lacks that story telling method. Many unnecessary pauses, dialogues and fight scenes. ML and FL were good at there job, but not best. Supporting characters were better than leads. It seemed like FL was not that good when it comes to emotional scenes. I've seen many k dramas where when an actor/actress is portraying 2 characters in same series, they do a better job compared to this.
But overall I RECOMMEND you watch this series of you love fantasy genre and finished all the best ones and looking for good ones.