I think your detailing and textures are totally awesome, but his left arm holding the weapon looks like it doesn't belong to him. I saw in your other piece that the character had a similar problem, and if I'm not mistaken - I think you are attempting to show perspective? Closer = bigger, Farther away = smaller? Well tiz true concerning perspective, but your arm seems to not only be a lot smaller, but also less muscular than the other arm. It is also placed a mite lower than the other shoulder. If you drew a line across the top of his chest, following the direction of the pectoral muscles, you would see that the line angles up slightly. So if anything the far arm should be higher than the closer arm, following that line of the body (I would draw you an example, but that is best suited for the forums). If you only beefed up that arm and made him own it more, I think there would be little else to critique in this sketch! :) You've a real talent in that head of yours, if you can learn to master the anatomy/bones/perspective more. These are also my weak points (as well as lighting), so you are not alone! We can only continue to practice, practice, practice. Hope to see more from you!