I'm relying on memory here, if there's some errors feel free to correct them.
In the novel, Cangju activated a poisonous smoke saying its the most poisonous item he has and expects Xie to be dead in a few seconds, lo and behold, Xie actually counteracts the poison with a cure-all antidote. Cangju was then poisoned back by Xie and Cangju asks what the effects are sine he feels his face itchy and uncomfortable (?) and mockingly says his face is already ugly enough. (it was implied he has bumps all over his face, compared to him looking all wrinkly due to his old face..) And the reason why he hates(loves?) handsome men like Hua yao is he is jealous he couldn't have their face, so he just tortures good looking men as revenge I guess. Anyway, back to the poison. He looks on a basin of water and sees his face became smooth and handsome. He cheers for a while saying he has finally become beautiful. After a few minutes, his face slowly melts and begs for Xie (the panel of him groveling over Xie to give his face back) to bring (it) back and he can give her anything she wants. The poison ompletely disintegrates his face and his dying breathe he says I just want to be beautiful then ppof, he dies. Hua Yao used his bone shifting ability and then copied Cangju's Appearance, but can't change skin (Cangju is wrinkly bumpy while Hua yao is smooth) so Xie applies some medicine on him to make his skin wrinkly, then out comes the panel about them leaving the room.
Like I said, I was relying on memory so some details may be incorrect, but the end result is the same.