I agree with what's already been said, the skin shading seems pretty good, although i'm a little confused as to your light source - his left side of his neck is in shadow, whereas the left side of his face isnt, and the light extends really high up his neck on his right, whereas similar place in his face is in shadow - basically, it seems like there's a frontal light source on his face, and a light source to his right on his neck.
The lineart itself is awesome though, as well as all those sketches in your previous post - i cant believe you can draw all that in such a small amount of time!!
edit - you posted your new picture whilst i was writing my message! the hair looks much better with more variation in colours - although what i said about the inconsistent light source is still there, as now both sides of his head is in shadow, and the top in light, suggesting another light source to how his face and neck is shaded