This is pretty cool. I really like all the detailing on the armor but it sort of falls apart when you see his head... it's HUGE for the body. I can see why you used it (it would be properly proportioned on an unarmored man) but you have to remember that the power armor would add quite a bit to the mass and mess with proper head size. Also his left arm is sort of gimpy... You lose points for the strange proportions but you gain them back for the painting, some good looking weathering, skin, and excellent freehand on the cape. Overall a solid piece.
I can only imagine how good those minis that placed were. This is amazing, and the level and amount of detail are astounding. My only critique is that the gore on the blade looks a little rushed, and there is not enough gore on the power claw for the viscera that is hanging there. I really like the raised filigree on the armor.