I just finished this show and I have some things to say.
I found the beginning of the series intriguing and it managed to catch my attention, however, as the series progressed I felt that I lost connection with the story and the characters, which didn't seem to have a major development within the plot. In the end, everything was just cruelty and sadism leaving aside other aspects that would make us as viewers feel something more than just disturbance. I don't think the show did everything wrong as it somehow made me want to finish the episodes but I do feel, and I agree with other reviews, that it lacked something more. Also, there were a lot of plotholes and things that didn’t make sense (like they could just buy a toilet in the common room). anyway I give it a 7.