Faerie Vandal and Sheoldred reward you for simply playing the game and drawing two every turn. Faerie Mastermind, Orcish Bowmasters, and (again) Sheoldred punish your opponent for doing the same. Since most of these are excellent tempo threats anyway, the rest of the deck is pretty much just counters and removal. 

Snapcaster Mage is probably the first thing I\’d cut if you want to play around with it. I also tried Grixis with Irencrag Pyromancer (which was solid) and Improbable Alliance (which was terrible). Overall I prefer keeping it two colors.