The upper left is distracting, and you can kind of see through the smudging in the fog stuff in the middle. Try to make the line of fog/no fog less visible. And add some text!
Part of the word "TYPE]" overlaps the focal's head... also, it looks like the "TO" in the middle of "[PROTOTYPE]" would be squished together, because the area that his head is covering isn't big enough to fit both letters if they are the same size as the rest of the text. Also, the spatter/grunge effects on the text should be in a gray or blue from the background of the sig, not in a brown color. The brown doesn't really fit. The smudging in this piece is pretty good, though the edges of the center smudging should really fade more smoothly into the background. There should be a light source to the upper left of the sig, because the background and the focal appear to have light shining on them from that direction. The red on the focal really doesn't fit with the gray-blues of the rest of the sig, you should either desaturate that part or use a gradient map to blend the colors better. Overall, this is a good sig with some very nice smudging. Nice work.