The so-called evolutionary effect of two opposable thumbs on either hand is hard to fathom. I'm not sure if it would enhance their intellects as one is plenty for handling tools. Still, it looks cool and exotic, and for something to sell, that is often sufficient.
The facial details are a little clearer. Lev sports a mean squint in permanent furrow that stares you down cold, while the horns seem ready to converge near the top. They embellish his height, but are likely ill-disposed as weapons.
It is clear that this was an interesting design that got the graces of shading--not a full-body design (which is required for a team of artists to base its efforts on) but design nonetheless--yet I have to be frank that this showed its origins in how it resembles a small desktop posing model. Everything from the ball joints to where the abdomen ball should be (made vacant and emaciated with Lev's slender design).
The slenderness does not help in giving the character any bite, and the otherwise smooth rendition of single pieces of metal does not convey a sense of menace. Other graphical touches, such as the incorporation of little rivets that resemble scales, or the inclusion of asymmetry with sporadic patchwork of random replacement parts over the many, many years of fighting wars (as stated in Lev's biography), might demonstrate better the freak's megalomania and sinister edge. Expanding upon the strange heraldry that appears on rough occasion across his frame may also help out a bit.
You're on a proper track, of course, judging by the sharpened teeth and the grandiose design. I would have gone far to suggest that the wings are worthless for the design but, as you pointed out, they were not shaded so as not to detract from the rest. I cannot give an opinion on them as a result. But usually this is bad since people tend to seek out a completed product instead of unfinished, progressing, or cancelled works. This is of the very last, though I see the reasoning.
Overall, nice work. Again, if you ever manage to make this world a published reality, shout it out, will ya?