Low Poly demon 5k Triangles

This is a work in progress in my own re-imagining the cacodemon from the game doom.The demon is intended to be a game model so my target poly count was 10k tris. After retopology, rigging and creating some animation in maya I test rendered in ue4 and the results are not as I wished for. I plan to increase the polycount and go back to my sculpt for a second attempt. I will make it more asymmetrical and some more teeth and improve the gums e.t.c. I think 10k traingles were too restrictive for what I am trying to achieve.