SPOILERS ALERT - Were you shocked...

... and also in any way surprised that in this movie, the psychotic killer, main antagonist of the piece, turned out to be SPOILER ALERT, Virginia, a pretty looking girl, even if she may have also had childhood trauma (that is revealed in this movie) that made her mentally ill to the point of killing, and I gather those people did NOT deserve to die EITHER, did this surprise and shock you?

Given how for the most part, and in these types of slashes horror movies as well, it is USUALLY men who are the main killers and perpetrators and with one scene in this movie ALSO, I even PERSONALLY THOUGHT it might have been a man, as it involved some serious physical strength in a scene involving weight lifting?

Also, how come, even if let's say neither of them wanted to kill her, but in the scene towards the end, when at least one of the men discovered her being behind the killings, with several bodies in the room and a birthday cake, how come neither was able to confront or defeat her or at least contact the police authorities so she could be arrested (and don't tell me that because she was a girl or woman, such men simply were against her facing harsh consequences even when knowing she killed people, or had a battle of conscience against confronting her, so as to avoid by mistake being labelled sexist or misogynistic, he-he), was she this intimidating?

And finally in the movie, when she was revealed as the killer, even knowing the childhood trauma, were we supposed to feel sorry or her or root for her to face consequences or even get defeated in self defense or something?

What do you think, thanks.