If it weren't because I liked the actors I would have stopped watching after episode 4.
Everything in the first four episodes showed promise, and it had an interesting concept but it was just that, all promise but no real pay out. For about 8 episodes we muddle through an annoying triangle that is so lopsided that it's like almost impossible to maintain, and yet the writer does and it's horrible. And then it just trudges on with no end.

I didn't mind the acting, actually that was it's only saving grace, they had charm but it wasn't really enough to sustain and ignore the horrendous plot holes and the dumb storylines that cropped up in the drama. So while unnecessary story lines were brought up, the real interesting parts weren't really explained. And I love Lee Jonghyun but he's no Lee Junki and he cannot make me turn off my brain with his charisma like Lee Junki can (ie: scarlet heart ryeo )

Fantasy is great and all, I quite love it and it's been my favourite genre since childhood, but the most important thing about fantasy is that it must make sense in the world the writer has created, it can violate whatever real world logic it wants, but it must not defy the story's own logic, and this drama didn't even establish anything until the very end. And by then I didn't care anymore, and within an episode they dropped what was just barely explained and what was fatal for someone wasn't fatal to our protagonists... hmm. yeah I was really pissed off that the writer basically drove the story to the cliff and then nonchalantly ignored the 100000 meter fall and skipped to the next cliff without showing the bridge the characters crossed on.

so basically don't watch unless you're a fan of the actors because if you aren't you'll really feel the complete waste of time it turns out to be at the end.