What I'm getting at is that Darksiders doesn't need to make itself stand apart from the crowd. Take a good look at Guild Wars 2, an upcoming MMORPG by ArenaNet. GW2 is anything BUT revolutionary; all it really does is grab pre-existing concepts and mesh them together. Like Darksiders, it blatantly "rips off" ideas from giants such as Blizzard's World of Warcraft, but it does so in a way that makes GW2 absolutely engrossing and overall an addicting game. To outsider looking in, it is nothing but 'another MMO'. But once you get into the world, you'll see that through grabbing a bunch of pre existing concepts, Guild Wars 2 manages to provide awesomeness in its purest form (speaking here as a beta tester -- the game literally had me up for hours and hours on end).
The same could be done with Darksiders II. It need not make itself stand apart from Zelda, AC, God of War, Pokemon, whatever. All it needs to do to become that next big thing is to blend the topics together in a sense that makes it an amazing, must pick up title. Oh, and some PR campaigns could work too.