Sorin of House Markov // Sorin, Ravenous Neonate

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, then return him to the battlefield transformed under his owner's control.