Reincarnation: The Root of All Evil (TROAE) will be the first full-length game for the series, containing four chapters to play through. It has not been released yet, but there is some information about the series on the Kickstarter webpage. There is also a Steam Greenlight page that gives additional information.
The game is supposed to start out with Vile capturing his six-hundred-sixty-sixth Reincarny. To celebrate, he and some demons drink until they pass out drunk. Vile awakes to find Hell has changed greatly, and no one knows what happened. Vile must find out more about what happened and help return Hell to its former glory, otherwise Hell might no longer exist. A lot of background information is also supposed to be revealed about previously introduced characters, such as Riley and Cain.