Cards like Orzhov enforcer and footlight fiend have effects when they die. Pawn of Ulamog, Mayhem devil and Gavony reward you when you sacrifice and in some cases when your opponent sacrifices a creature. Use both Krenkos, and young pyromancer to keep making 1/1 creatures to sacrifice.
Finally, several spells you cast cause you and your opponent to sacrifice creatures which activates several of your creatures abilities, thus making an extreme combo.
