(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.) Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.) When you unlock this door, return all creature cards from your graveyard to the battlefield.