Sorin of House Markov
Lifelink
Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
At the beginning of each of your postcombat main phases, if you gained 3 or more life this turn, exile Sorin of House Markov, then return him to the battlefield transformed under his owner's control.
Sorin, Ravenous Neonate
Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
+2: Create a Food token.
-1: Sorin, Ravenous Neonate deals damage equal to the amount of life you gained this turn to any target.
-6: Gain control of target creature. It becomes a Vampire in addition to its other types. Put a lifelink counter on it if you control a white permanent other than that creature or Sorin.