hey, that sprite is really good, it has a good use of terminator shade and a exceptionally clear lightsource.
those chains are completly killing the depth of the pic, because they kill the illusion of the pitch black darkness, I also think the perfect circle on the back kills all it's volume since it isnt affected by the muscle shape, and just seems to float there.
This stuff just makes him seem like...a wanna be pimp or something with all the gold, I'd put something to emphasize effort or pain, like rusting restrains, or maybe a fakhir style blade trough his limbs, or a burnt in tattoo (tattos made by scarring)
Eitherway, go back to the basics of the char, remember why you put that protuding deformity in his shoulder, what it meant to you, try to express that with any add-ons you put there.
I really liked the portrait too, seems like you're buclking down and doing some real shading, I cant wait until you implement the concepts you did before with this more down to earth aproach, before they were just aloof ideas executed badly, but given you keep the basics right they can work great.
