
Whenever one or more cards are put into your graveyard from your library, each opponent loses 1 life for each card type among those cards.
(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, millmillPut that many cards from the top of a library into its owner's graveyard. three cards, then return a creature card from your graveyard to the battlefield.
(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.)
Hover an underlined rule to see what it means.
Read from the rules text. A card that enables a keyword makes or is the thing; a card that rewards it gets better when you have it. Two cards interact when one enables what the other rewards.