I like what you did with it! The palettes are great. The shading is very nice, i specially like the hands shading and detailing.
The main problem i see is that you need to pay attention to keeping the anatomy more consistent; the parts, individually, seem correctly shaded, but as a whole, things seem to leap to where they shouldn't be, not conveying a solid volume look.
The major points i see is the back, head position and "lower" torso: i think the back and lower torso should twist
away from us instead of towards, and the head doesn't fit well in that position between the shoulders, looks like it's pushed to our left too much; should be moved to the right quite a bit, i think.
(some of this may come inherited from the original lineart, which had some odd limb twistings)
Try sketching the thing in basic blocks - cylinders for limbs, spheres for joints, etc. - and remember to keep the perspective consistent, and it will aid in keeping a more solid look.
Despite the crits, it's nice work, and i'm honored