I think you're looking for Junichi Hayama. He was the animation director for episodes 5 and 10 of Shin Sekai Yori as well as on staff for the other 2 shows you've listed. Some of his other works fall into the same characteristics you listed.
You can see some of his art from a Google image search
Among other works:
Afro Samurai: Resurrection (movie) : Key ...