This is pretty cool
The black and white environment isn't helping this piece at all, in my opinion. It's really distracting.
I'm mostly bothered by what you did to his right hand. He looks like an amputee, hard to see that his arm is connected to the weapon. Also the weapon itself drawn pretty poorly, perspective wise, usually things get bigger as they get closer to us.
The lower part of his bodies need more addressing, hints of muscles like you did on his upper parts will definitely help his tights and shins.
You also need to make it less flat - more shadow and more contrast almost everywhere. I also agree with Ex Nihilo's comment.