Source
Changed to include Auric Interrogators and Surgeon's Saws (see changelist). I also changed the powerbase slightly as the original author didn't take into account the Shadow sources from Vara's Favor. This brings both Unseen Command and Auric Interrogator to 75+% on curve.
Auric Interrogators are better to play on an empty board and synergize better with Tavrod.
Bloodletter gives more instant stats, but Surgeon's Saw's lifesteal makes card draw free with Fenris and Auric Interrogator, and the spellcraft is very useful in a deck that relies on units to win. Consider running a 2/2 split.