This looks really cool, and even without colour it looks nice.
I really like the face over here. It looks so well done, with a lot of detail, and the beard looks really cool too. As Fro said, though, the ring on his head was a little roughly drawn, and the gun needs some more texture and detail to it, even though it looks really cool right now. I wish this had a cool background too :\.
I won't complain about this needing any colour, since it looks really awesome without anyway. The shading here is perfect as well, especially on the face, but on the gun it needs a little work.
In all, great job, when it comes to madness sketches, you're the best at it that I know. Actually, the best at any sketches from the Art Portal. Keep it up ;).
-Review Request Club-