I didn't have much expectation for this show as I was watching it because the storyline seems really interesting and Taecyeon is inside.
However,  Woo Do Hwan totally stole my heart so much more than Taecyeon (I'm so sorry) I ship Dong Cheol because he is so true to himself even though it got him into so much trouble. (He's so dashing too)

This story really shows that how extreme certain people may be after having faith in the religion but this show made it real bad and disgusting. How disgusting humans can be in order to gain power and how bad the society is. Be it in the show or not, some times it's just how the society works nowadays. The rich gets richer and can do 'mostly' whatever they want to have their own personal gains.

Storyline is amazing. Full stop.
Nothing like what other kdrama would do, not much of a love story but a lot of kinships and bromance.
Bromance game were quite strong despite some 'loop holes' that i find it weird but nah.. Not allowed to give you spoilers.

Every cast has their own story at the end of the day and that's what makes this show perfect. All cast be it supporting roles or main roles, they did their part to make this worth while. There are characters that you would be disgusted and also some surprises here and there when they happen to discover more  secrets.

Music wise i don't really remember much except some sad scenes and not forgetting the initial "15" introduction part by the main female lead (her voice is gooood) though i don't understand what she says everytime at the beginning, heh.

I wouldn't really rewatch this show as i wouldn't say it's my real favourite. (I don't really rewatch shows unless it's my REALLY REALLY favourite if you get what i mean)

But that doesn't mean it won't be your favourite since everyone has their own preference!
So please, enjoy the show and discover some secrets in the cult!