Polluted Cistern / Dim Oubliette

Condition: Near Mint
Color: Black
Card Text: 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, mill 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.)
Rarity: R
Cost: 1B // 4B
Card Type: Enchantment - Room // Enchantment - Room
Artist: Arthur Yuan // Arthur Yuan
Name: Polluted Cistern // Dim Oubliette
Finish: Regular
Card Number: 0023
Set Name: Duskmourn: House of Horror Commander