Yeah, it's a bit disappointing nobody is bringing up the massive chasm between immediately offing oneself for hurting a fly and unrepentantly toying with, torturing and the slaughtering people without pause. It's one thing that some characters might as a flaw to highlight, but trying to disappear it from the narration without either convincing or distracting the reader is really bad writing, as they are sure to ask the questions the author seems content just skipping past like this.
But let's be honest: This story seems really disinterested in expanding on anything that isn't the two main characters, IMHO to it's detriment.