It is hard to find something nice to say about this. The picture is rubbish. Can't even tell what it is or the color. A cover-up might be the best way to go. Post a better pic if you really want input. Sorry.
I am awsome at being nice. If this design is something he wants to work with, then a back piece would work well with this. I just don't know what it is. It looks tribal-ish. So expand on that.