So I have been working into the Villain. His body shape had yet to be found. Here are a couple of experiments. The first of which I was playing with the clothing what with the villains character being the closest to human compared to the rest of the hybrid race. (He was born a human and then evolved into a tortoise hybrid) Therefore he would most likely cling to human conventions and culture more than any other.
Below are a series of silhouettes in which I tried to play around with the proportions. I currently prefer D although I might straighten him up slightly. At least here there is clear indication of a shell like form complete with the claws of a tortoise. Although rather than three digits there are going to be five per hand.