I think we should start brewing towards the new draw spell that was leaked. Someone less lazy than I am will link properly if need be but it basically reads:

B
Instant
As an additional cost sacrifice a creature.
Draw 2 cards.
From M21 is memory serves.

I think it fits perfectly in grindy combo builds of all sorts, especially when you can incorporate things like Veteran Explorer, striges and other ETB effects / mana effects as well as enable Cabal Therapy as disruption.