Ashen Ghoul

Haste
{B}: Return this card from your graveyard to the battlefield. Activate only during your upkeep and only if three or more creature cards are above this card.

Bone Shredder

Flying
Echo {2}{B} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, destroy target nonartifact, nonblack creature.

Putrid Imp

Discard a card: This creature gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, this creature gets +1/+1 and can't block.

Waterfront Bouncer

{U}, {T}, Discard a card: Return target creature to its owner's hand.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Cabal Therapy

Choose a nonland card name. Target player reveals their hand and discards all cards with that name.
Flashback—Sacrifice a creature. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Ichorid

Haste
At the beginning of the end step, sacrifice this creature.
At the beginning of your upkeep, if this card is in your graveyard, you may exile a black creature card other than this card from your graveyard. If you do, return this card to the battlefield.

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. This land deals 1 damage to you.

Careful Study

Carrionette

{2}{B}{B}: Exile this card and target creature unless that creature's controller pays {2}. Activate only if this card is in your graveyard.

False Memories

Mill seven cards. At the beginning of the next end step, exile seven cards from your graveyard.

Mesmeric Fiend

When this creature enters, target opponent reveals their hand and you choose a nonland card from it. Exile that card.
When this creature leaves the battlefield, return the exiled card to its owner's hand.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Engineered Plague

As this enchantment enters, choose a creature type.
All creatures of the chosen type get -1/-1.

Ertai's Familiar

Phasing (This phases in or out before you untap during each of your untap steps. While it's phased out, it's treated as though it doesn't exist.)
When this creature phases out or leaves the battlefield, mill three cards.
{U}: Until your next upkeep, this creature can't phase out.

Squee, Goblin Nabob

At the beginning of your upkeep, you may return this card from your graveyard to your hand.

Hapless Researcher

Sacrifice this creature: Draw a card, then discard a card.

Chill

Cephalid Coliseum

{T}: Add {U}. This land deals 1 damage to you.
Threshold — {U}, {T}, Sacrifice this land: Target player draws three cards, then discards three cards. Activate only if seven or more cards are in your graveyard.

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Annul

Counter target artifact or enchantment spell.

Swamp

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.