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 your postcombat main phase, 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.
