What was the point of Quintin...? Spoilers
Killing and attempting to kill the remaining survivor (Kazan) . I get that they left him for dead, but he wanted to leave the austic guy behind and he was alive and proved useful towards the end. I mean the fact that Quintin would waste the last bit of energy killing these people so close to their escaping out of the cube is ridiculous. His character was very aggressive and cold but for him to murder them, especially the girl who really was responsible for saving them is really weird.
Maybe him being in the cube turned him into a psychopath?