Forgive me for not reading all 9 pages of posts, in case this has already been mentioned:
Amazing technique, but how was this achieved? I mean, the silhouettes are so sharp that I suspect you are using paths to mask them, but then again, you even manage to create super sharp shadows inside the characters. It is so super clean, and really impressive. But I guess it also leaves a metallic feeling to some things, which you might have to be careful of.
The left side of the giant in "Beneath the Blackened Heavens" have zero of the light from the sky reflecting on his skin. But this might be done on purpose, because his right side does have it, especially on his arms and leg.
Other than that, your style looks like a HDR effect done right, and the fact that it's done by hand is probably the most impressive thing I've seen in many years.
Art should tell a story. Don't paint a moment, paint a lifetime.