Fading into black is a classic lighting technique made famous by the painter Rembrandt. Dropping someone into a sea of black really forces the focus onto them.
Heavy shadows and strong direct lighting is something I love to use to create uncertainty with in the photos.
Mixing these two techniques is something that I've done in the past to great success and I'd love to use it again and print it nice and big.
Some of my previous photos that show these techniques.
I'm going to base this whole shoot around this shot.
A few examples from around the web.