This image is very well composed! I really love the cross-shape in the background, it draws the eye around the piece nicely. I love his expression in both parts, he seems to be a fascinating character to me. The colors are well coordinated.

The only thing I think you can improve upon is the inking. The lines are a little shaky around the characters--if you try the vector tool in photoshop to get smooth lines. I usually ink my sketches off the computer, so I can't really give you too much information on how to use it, but it looks very good on other people's artwork. So give it a try! :) Keep up the good work!