I always did think Vega was pretty cool, and I think this is the same. Im not really sure about the splash of shadow colour thingy in the background, because I think it would have look just fine without it. Also, I think what is bothering me about the image is the balance. His hair, the sash around his waist and the claws on his hand all pull to the left and thus outbalance the other side of the image, add to the fact that his claw is cut off at the edge of the image. I think it would have looked more appealing if the claw wasn't cropped, and his hair and sash blew in the other direction instead, to balance it out.
Saying that, the pose is really cool, and the anatomy is very good. So not really much to complain about this image. I like it, well done