For me it wasn't that slow people ought it to be. If you are a fantasy and thriller lover than you must watch it. For me the best part was Lee Jin Wook's acting, the ost and the bgm. Fully top notch I say.
For me the only draw back will the fml's continuous crying but you will get used to it at some point. Lee Joon fully slayed the role as a villain, honesty I was terrified every time he appeared on screen, that is the proof how impactful he's acting was.
So overall I would give it a 9.5/10 ( Happy watching 🤗)
It's my first review so pls forgive me if I make any mistakes.