Welcome π
@Davidson: you could use the same shader to remove the coloration from the character then tint it black, yea. If you wanted it to be a semi-transparent shadow though you would still have the same problem of the jointed areas that overlap being twice as opaque. I would also be sure write new code to do this since SkeletonGhost clones the meshes every time it generates a new frame :X Don't need that for shadow, you just want a different renderer to render the same mesh but at a different angle/offset and different material.
@Rob:
He's workin on it heh. it looks better every time I see it.
edit
Actually his drivers license fell out of his pocket last night when he was over here for our coworking/co-op gaming night. I might hold it hostage until the shaders are done. hmmm...