How do you keep it contained?
You have a very nice description of the containment area, which would be affective for many scp's. However, there is little within the containment section that actually tells how they stop this particular scp from escaping containment. If I read it correctly, this particular specimen can fly, however there appears to be only the measure of personal shootingdown/attempting termination against this scp. The gates thus only serve as a ground containmnet, not an air (keep the gates though, they are nice to make sure no one gets in :D).
I would most deffinitly up the guard, 2 seems too little for a predatory scp like this. The reason I say this is this specimen seems to have a habit of trying to escape when its out of its dormant stage (i only assume so as there is warning too stop it from doing so, which could mean it has tried before.)
I like the fences idea for a ground based containment, it also helps to keep out unwanted civilians (as i assume this containment is outside of the foundation facilities.). However I would add something too keep it from escaping via flight. If the unit can regenerate/enter a dormant phase via termination. I would look up some anti-drone weaponry of somesort, something like a small self guided turret too keep this scp from being airborn. I would also find a way to move the scp during its regenerative phase/starting of dormant phase back to the center of the radius, so that it hasn't gained any ground in an escape/breech attempt.
Edit: Upon reading closer I realised that there are actually 16 armed guard on sight, I don't think you need too add anymore XD. HOwever, i would still add an anti-air security measure, as mach 7 is still increadibly fast, and is very hard too shoot at.
how does something without facial fetures eat.
Perhaps I took this too literal, perhaps it has facial fetures but not defined. If I am correct however, and it has no facial fetures, how exactly does it eat its prey? or is it more of a senseless kill, not to eat, but just to kill? This is something to think about as it will affect the description of the scp.
Edit: Reread it and I understand now, I believe you ment that it had no skin on the face, so it was very skeletal esq (I think, please correct me if I am wrong :D) if this is the case please ignore the above suggestion XDXD, feel free to call me an idiot though XD)