Creatures and combat are essential parts of the best Cube experiences for my money, and keeping creatures in check should be one of blacks strengths
Personally, I see less than 10 real stinkers, with Tasigur, Lavaclaw, Wildwood, and Balefire being the real stand out failures, but the real question here is how much middling promos like Ulamog or Creeping Tar Pit will end up at, and how much the true maniacs like Liliana of the Veil will drag the mean upwards
But there was one space we hadn't really explored, the hand
Best Recursion Creature Payoffs Recursion creatures tend to work best with sacrifice or self-mill strategies
Shock is a reasonably playable card, though you need some form of upside for it to be worthwhile
The other cards that tempt at common are virtual vanilla creatures or simple effects like Sam's Desperate Rescue, Soothing of Smagol, and so on