Shading refers to depicting depth perception in 3D models or illustrations by varying levels of darkness.
https://en.wikipedia.org/wiki/Shading
Robotics Sword Cave Shading
Because some cyborgs need swords apparently
His face Il visage Face Portrait Shading Brown Nose Pink Peach Petal Ear Head Skin Finger Lip Neck
"I wanted very much to learn to draw, for a reason that I kept to myself: I wanted to convey an emotion I have about the beauty of the world."
Ichiro the Cyborg Swordsman
Robotics Sword Cave Shading
Because some cyborgs need swords apparently