Sorin of House Markov

Each transforming double-faced card in this set is cast with its front face up. In every zone other than the battlefield, consider only the characteristics of its front face. If it is on the battlefield, consider only the characteristics of the face that's up; the other face's characteristics are ignored.

The amount of life you gain from extort is based on the total amount of life lost, not necessarily the number of opponents you have. For example, if your opponent's life total can't change (perhaps because that player controls Platinum Emperion), you won't gain any life.

You can activate one of Sorin, Ravenous Neonate's loyalty abilities the turn he enters the battlefield. However, you may do so only during one of your main phases when the stack is empty. For example, if you control another permanent with an ability that triggers at the beginning of your postcombat main phase and that ability is on the stack below Sorin of House Markov's last ability, there will be an opportunity for your opponent to remove Sorin, Ravenous Neonate before you can activate one of his abilities.