Every single portrait is 101% perfect that doesn't deserve any criticism -- somehow you've transported to their world and back and have created flawless representations of what they'd look like in real life (based on their defining features in the anime). The way I feel is no secret based on what I've commented on your other works. And yet this'll be the only time I'll ever, ever criticize you. The only thing that I think (in my personal opinion) is off about your interpretation, is the nose. One of Reiner's defining traits is his nose, which is distinctly shaped compared to the other characters and (key word coming up, is a bit*WIDER*. So I think the nose should've been a little wider; this nose here looks (noticeably) thinner and a little 'too' normal. Nonetheless, when I look into this man's face, I without a doubt see Reiner, so you definitely captured the likeness.