The overall figure is very well drawn. The stance is good and looks very powerful. The coloring is very well done, smooth transitions in the shading along the cape and body. You ahve a great sense of the figure and the lighting of it.
My only real criticism would have to be that the shading suggests that you've got multiple light sources that conflict with one another. The heavy shadowing on the face/forehead suggests the light comes from somewhere around the "floor". That is carried through on the chest and arms but the abs seem a little "flat" since you've done one, broad shade there. The trunks suggest the light is coming just from the left. Then, you even it out again on the legs and boots. The cape suggests the light is coming from directly head-on.
This is a great piece, overall, and you really know what you're doing! Just a few tweaks and this will be OUTSTANDING!!!