Omg, YES that was the scene that did it for me too! I always thought she was a little not all the way there after killing that horse, but when she said that about Dohwa's flowering it was just too damn creepy. Seriously, Yoosun needs several years of counseling cause she is too warped in the head.
She is obsessed with Dohwa, it's not healthy
And that blue jewelry.
ops, wrong reply haha
At first I was team Yoosun as many of us fans I think, but the deal breaker for me was the scene where Yoosun says she's kinda excited to deflower dohwa, I mean... 2 rude 4 me, kinda sounded like a gross old man talking about a little girl... HUGE UGH! but look at how things turned out... YOU LOSE, YOOSUN