In the last two, to my eyes you seem like a Sheakesperean actor delivering an ode to the saw.

But that's really a criticism.. by contrast it shows the sesne of twistedness (and readiness for violence) contained in #1. I think having the saw overlap you face really emphasizes that .. I cna't see it now but was it even the point of the teeth lying against you face (in the frame))...very sinister and twisted. You body posture was right in the first frame.. with the second, I'll still gettin 'normal actor'.
This post is now ranging into acting, where I hve some intuitive abilities with no actual acting experience. Before the shoot, you put your self in the right frame of mind by running through some fantasy violent scenes. Lean how it feels to use that saw, which had is most comfortabl. How you want to sneek up on your victims. Then notice body movements.. do you move jery or smooth? Do you movements feel sinister or not? Whichever movement style you are doing, try the other one.
I think the most sinister villians, and you have a achieve this in the first photo, are the ones that demonstrate the potential for gerat violence, which you can see just by watching them, and at the same time have a cool, controlled exterior. I was just playing with this now, and I started by making violent slashing movements with the saw. Then I saw there and did some small movements, just picking up a cup, in a smooth way, but with some of that sense of violence mixed into it.