Nice shading and I really like the mood of this piece. Pose is dynamic and interesting. I like eyes in the background, and colors are awesome looks evil af.
im not really sure what's going on with the hand the middle finger is rather too long or too skinny and fingers don't really bunch up that way around the thumb, you may want to practice drawings hands. You may also want to try using a custom font instead of writing with a brush for a more professional look, unless its your signature
great work on this and looking forward to more.