After the rotation of M12 and the Scars block, I was able to do a little tweaking. Put Havengul Lich back in for additional graveyard reclamation/utility and added the following: Blood Artist to put additional threat on my opponent from killing my creatures, Think Twice for a little card advantage, and Spectral Flight in case there are any fliers (or to gain that advantage if there aren't). The new focus of the deck is to directly damage my opponent as he kills my creatures, forcing him into a defensive position as I build up.
Thinking about Altar's Reap for card advantage instead of Think Twice; it would give me another sacrifice mechanic to force loss of life (possibly for the win, if my position is good) and triggers morbid for Tragic Slip.
I usually manage to get at least one of the heavy hitters (or Rooftop Storm) out, but find myself running out of a hand and getting mana flooded. Thinking about going down to 20 land - my curve really isn't that steep, after all - but don't want to push my luck. It's also very possible that I'm bad at shuffling, try though I might to discover a better way to do it.
Suggestions for sideboard would be very much appreciated. Freshly back from sea and still getting a handle on the new set. Tried to splash in some green for Golgari goodness, but just wasn't worth it with my dearth of dual lands.