The latest issue of the 9th Scroll is here!
You can read all about it in the news.
Are they undead? Their gray flesh makes them look like they're undead.
Oh no no, these pale faces bloom from their immediate realization of their purpose on the battlefield, as the moment occurs! - Nah, the camera might not pick up the slight pinkish hue of their skin well, but you are correct they are rather grey and filthy.