Diablo III and thought that the game would be better if you were playing alongside the villains? Considering the fact that angels in that game are also tremendous jerks, it's kind of an understandable thought. Inferno Legend is meant to speak directly to that impulse, putting players on the side of Hell and the demons fighting back against legions of humans, angels, and similar antagonists trying to kick you out of hell.
Taking the role of Vampires, Mummies, Cyclops, Faeries, or Samurai, players fight back in a turn-based Diablo-style environment. It's also boasting synchronization between browser-based gameplay, mobile clients, and traditional desktop clients, so you can play however you please while still making progress. The game has just entered its closed beta testing today, so if this sounds like just your cup of tea, you should go ahead and sign up in hopes of taking part.
[Source: Changyou press release]