IMO, the triangle of darkness in the middle of the image is not doing any favors for you. It seems that the flash was pretty much pointed at his left ear, which causes the distinct shadow line on the opposite side. Typically a 45° from camera is used for portraiture. A reflector (of some sort) on the opposite side of flash will increase detail on the shadowed side.
Also notice the nose shadow. Pretty much straight on shot, huh? This also creates that bright spot on his left cheek. Try raising the flash above the subject to have the shadow draw down nicely. The light falloff is okay, but the missing digits of his left hand would possibly have been brought out with a reflector.
I like the expression.