Some more movie killers that I just thought of:
First:
Samantha from Deadly Friend. Like the title says she will be a deadly friend to you. I don't know too much about her killings in the movie, but I know the infamous Basket Ball scene where she grabs a lady and throws her to the wall then Samantha grabs a basket ball and throws it at the lady's head and the lady's head explodes and the body wanders around the room. That was a sick scene.
Second and my favorite one of all time:
The Puppeteer from Ghost in the Shell Soild State Society. Now I don't even know if that is the puppeteer or if that is Motoko laying down and saying what it is saying in her Cyber Brain in the picture. Still it had no face at all, he just kept changing his face into different people. I can the puppeteer is an IT because IT changes his, her, ITs face making it impossible and I can't remember if he, she, IT had a man voice, but IT used a man's voice. IT killed people by hacking into their Cyber Brains and then forcing them to commit suicide.
Third:
Barb from Barb Wire. Even though the Nostalgia Critic sayed that the movie was horrible I really kinda liked it. Barb is a professional killer in the movie or assassin. I know she killed a lot of people in the movie, but I don't want to go through in detail.
Fourth and my 2nd favorite one:
Eureka from Eureka 7: Good night, Sleep Tight, Young Lovers. Yet another teenage killer. Although not a killer in the movie, although I didn't watch it yet she could have killed people, she was a killer in the anime show Eureka 7, in one of the episodes it shows a past where she is seen killing hundreds of people with Nirvash and by herself. She still counts as a killer in the movie due to that she was a killer in the anime series and she still killed people and that lives with you in for the rest of your life.
First:
Second and my favorite one of all time:
Third:
Fourth and my 2nd favorite one: