The lines, imo, go too much into the twisted 'I'm going to kill you and enjoy it' and less creepy but 'charming' vibe. Example: Ahri. I think it might be cooler to have her lines in her revealed form more like Ahri's (charming with a hint of creepy) and in her shadow form, having more of the twisted, 'i'm going to kill you' lines.
Of course, the creepy kill you lines could still come out, especially attacking low health champions.
I don't know, she was supposed to be able to seduce you, but I, personally, don't want to ever even get near her.