Little bit late for me to be writing a review, but whatever. It's been a while since I've been on this site anyway.
I like this piece, especially the attention to detail you put concerning the weapons and the armor that the demonic creature is wearing is not too flashy or ugly. It just seems so right on a being so down right vile, which you have demonstrated in this drawing.
I really have no complaints about this, although you could've have used a bit more color concerning the background and the demon's armor. The amour looks a bit too bland, but perhaps you did that intentionally.
Overall I found this a really good piece. Great job!