Well I'm not a 'critic', but this is amazing work. I like your style so much and I'm following your work for a long time by now.
You always convert those known characters into your style perfectly. This requires perception at it's best and you clearly have it! (As we already know.)
I'd like to add, Nathan looks a bit older than we used to be seeing him. Was that on purpose? Or maybe you went with the Next-Gen version, which he seems to be older than he was before.
This piece reflects his characteristics so good. His always-in-trouble state and Indiana Jones-y gear with his casual clothing.
In the end, you're awesome. This piece is awesome. When it's colored and has a background it will be on another level.