I tried out the spray fixative on the upper left part of the head to see if the white pastel would disappear. It seems that if you spray extremely lightly, allow to dry then spray again then most of the white remains OK. So with this in mind I'm ploughing on. The remaining part of the picture is to be very dark and I'm going to darken the right side of the face too so that it appears as if the lion is appearing out of deep shadow.
Although I had hoped to get a bit further on so that I could complete it tomorrow, at this point my hand/wrist is killing me so it's time to stop for the day. It's the one I busted badly a few years ago so I have to put up with a bit of pain when I'm working hard. (Oh how we artists suffer for our work)