There are no casings, and a high capacity, so that's an improvement on firearms. Lazers and what not would use more energy than they're worth. Joi is programmed to simulate contact, so showing water on wet skin that isn't there isn't a stretch. This videos have gotten really long and a lot less funny.
Two abdominal wounds, slashed left hand fingers, multiple kicks to the head and after all those injuries K kept on going and managed to kill her. He was more human than human.