It looks very good, the proportions and musculature are great; but I think it's actually a little too polished compared to the original. Don't get me wrong, I'm impressed with the way you cleaned it up, but the shading on the original really gave it a sense of character that this one lacks, so it just seems a little flat in comparison. It would be nice if you could find a compromise, and color it while retaining the shading of the original sketch.

Also, I'd suggest using a different color for the fire on his skull.

Overall, 4/5.

I like it, but it might need shading.