Grimwall Keep...?

Whatcha think? Looks like a suitably horrible place to exist.

A terrible fortification out on the far edges of the frontier, a place only desperate men (beasts?) are sent to redeem themselves and make amends for their past sins? Of course, tossing bad, and possibly irredeemable, people together into a miserable place only fosters the right conditions for the vilest things to happen. These people struggle to find a way to survive in the middle of a cataclysmic disaster on a level never before seen. The forces of chaos stir over the wall, summoning the worst from the dark planes to man the rosters of their dark force. The Devil himself is said to wander the forests, eating the hearts of men and committing atrocities against those he finds in his lands. He twists and contorts their minds until they serve him without regard for themselves. 

Grimwall Keep serves as the defense against this evil, all while being manned by some of the worst of us. Can mankind survive?