Looks cool. The darkness arounds him show the image good. I recommand to keep drawing more. Maybe even blizzard wants you in the future. Thats how some people got in make drawings like this. So if you live close to their HQ. Don't by scared to try.
I like the drawing, makes me want to get back into making proper digital art again aswell.
I do however like the second (sketched on parchment) and second last version of the skeletonking more, the one where the yellowish color on the background is still a bit visible. The last one could really use some more color variance imo.
But really, nice work man. Think im gonna try and makesomething again aswell :o