They all look great. On the Halo one, I tihnk it would look a hell of a lot better if the bright spot was on his other shoulder...
On the first one, it would look better if the whole thing was a little bit sharper and the yellow bits below the text weren't there. On the second, I agree that the light should be on the other shoulder, and I would fix the text, it looks blurred and tilted. On the third, the render looks weirdly blurred and the text, I'm not sure if this was intentional, but you spell Scorpion with two O's
