This is not your typical idol drama but it's definitely an eye candy fest. You'll see many so many familiar good looking actors/actresses all gathered in 1 drama.

This is a quality production in a very dark setting. Ep 1 instantly got me hooked with the female assassin concept which remotely reminded me of Bloody Romance. The cinematography, CGI & fight scenes are all really good.
Make up on the MLs are a bit overwhelming but it works well on the FLs with the dark costumes. Costume designs are very beautiful with lots of black and fine gold detailing. Even the plain monk costumes you can see the fabric texture detailing. Quite impressive.

Storytelling & dialogue is engaging to where full attention is required at least the first 1/2. Story revolves some power struggles , murder mysteries, assassin frenemies making me wish this series is longer than just 24 eps.
Only parts I don't care for is the sister of ML. OTP forced humor feels out of place for this drama. A few lines were funny I admit but most I can do without. 2nd half though she did grow on me to my surprise. It's been a while since I loved almost every character and every fight scene!

Overall:
2nd FL & 2ML out acted the ML & FL
2ML's brother makes a great trio dynamic
Ending is.... tragically messy to the land of no where. Hoping S2 will magically appear one day and answer all unanswered questions.........................