I like this.
the sketch needed a bit more work though, a few design oversights.
I think the helm needs to come further down on the forehead though, and to have cool shapes like the sides, then you can get nice and dark and intimidating on the face around the eyes, also eliminates that awkward empty space under the helmet around the the forehead and stuff.
Or maybe just some slight bone protrusions around the eyebrows or something
just really need to do something that will sort out that awkward space. it widens the top of the head far too much and throws off all the proportions.
also the transition from the cheek pieces to the side pieces, either needs to be blended together or separated entirely, that rounded edge connecting the two pieces doesnt work.
blue: awkward space
red: weird transition