WOW! There aren't really words to describe this, but I'll try.
It's incredibly dynamic, the force radiating off him is just amazing. Add in the rippling effect on the arm and the clothing in general it just defies description. The only thing I'm not keen on is the eyes. Personally, for a dark character, I would have thought narrow and sharply angled like the brows. Perhaps red or florescent green or maybe even an icky yellow, but that's just my humble opinion.