I still agree with pkmays. I mean, with the shadow underneath his body, it still makes it look as if he is on a separate plane, DESPITE the fact that you mentioned the background is not supposed to be in conjunction with the characters themselves. If the shadow is to be used, then wouldn't it be more skewed to fit the strange inclination of the background? I would try removing it to see if there is a difference in the strange perspective it might be creating. Just a general opinion, though.