Hey Integrated, I like the concept behind this piece. The overall proportions of the base mesh seems fine to me, looks like the edge loops around the mouth could be reduced a bit. The detailing on the clothing is moving in the right direction, just grab some more reference to commit to some of the clothing volumes.
Some of your organic zbrush detailing could be refined a bit. I would say that some of the wrinkles in his face seem a bit too exaggerated, the forehead wrinkles should be much more horizontal, with less curve. The overall anatomy of the face could be tweaked a bit too. The ears could rotate forward a bit more, the mouth can pinch in a bit more in the corners. Overall, I do see a resemblance to del toro in your model, I think a little tweaking here, would go a long way.
keep it up