the main problem I can see is that the body dosn't really read as a skeleton, I made this Edit to illustrate some of my points:

I'm not sure if its supposed to be a skeleton with muscle's(if so then ignore this).
I focused mainly in the edit on making it look more ''skelety'', like the feet and ribcage for example.
but I also touched up the skull, I feel Gil's comment on the skull went (abit) unnoticed.
I think some things look a bit bland/boring like the skull and the sword, some details like blood,cracks, whatever should be added to make it look a bit less bland and generic...
Also you could use contrast to make ''important'' things like the skull pop more.
Anyway keep it up, I'm looking forward to an update!