Looking good on the turnaround! A couple of small things - I'm a little confused on what's going on with his boots (and to a lesser degree on his wristguard). I'm not sure how the boots are attached to his legs - the shoulder makes it clear that it's growing out of his skin, but on the boots especially, it looks like it's attached to the boots, not him. If he's got crystals coming out of the sides of his legs, a little thought as to how his costume'd work around it would not only make more sense, it'd make for a more interesting, creative design. Also, his skintone and clothing are all pretty samey, colour wise, a little more variation in hue and value could really make some important bits pop.
On the thumbnails, I really like number 2, though make sure to watch the tangents around the edges. =)