[Grislygus]

I don't know if I can offer tips that you would want on the first drawing, because it's very stylized and you obviously have a very clear idea of what you want to do with it. But from an anatomical standpoint, he has all twelve ribs below his chest, where his diaphram is. On a real person, only three or so ribs would be visibly below his pecs. You've got the diaphram right on, but only a few ribs would take up that space.

As I said before, it's very stylized and you're probably already aware of this, so feel free to disregard anything I say.

The second one's pretty damned good. The only problem I see is that his right arm is too short. I would also make his right hand open, but that is strictly a personal preference, and has little consequence on way or the other.