Your working on the metallics, and it shows
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The weathering/rust on the armor is pretty good, but I would add some bare metal to the rust on the right knee, and the serious rusting on the armor on the "flap" closest to the backpack is too powerful I think. The OSL on the gun is a bit rough as well. See if you can feather it a bit further out so that the line between the silver and blue isn't so sharp.
Personally I think I would have done the chest eagle, imperial markings and shoulder skull in a bone-ish color rather then copper metallic, to make the contrast between different materials lesser.
All in all a good job so far, and I'm fairly certain I couldn't have done it better
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/FF