The sheet says he is made of Porcelain but even that drawing doesnt have a pure white body. Try using a shade of blue and use white for the light from above then make the lower body much darker so that the light looks much brighter than it really is. Your anatomy is great but i curved his body so it looked like he was curving forward. Make bold choices with your pose, if hes curved a certain way than exaggerate it a little. Same with the shading, making the darks very dark so that the light is brighter. With lighting, follow the body forms so the top of the head, curve of the horns, the slant of the arm and the edges on the fist.

