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

Flying

Whenever you cycle or discard another card, put a -1/-1 counter on each creature your opponents control.

Cycling {2} ({2}, Discard this card: Draw a card.)

When Architects of Will enters the battlefield, look at the top three cards of target player's library, then put them back in any order.

Cycling {U/B} ({U/B}, Discard this card: Draw a card.)

Spells and abilities your opponents control can't cause their controller to search their library.

-1: Target player mills four cards. Then exile each opponent's graveyard.

Sacrifice a creature: Add {C}{C}.

Flying, deathtouch

When Baleful Strix enters the battlefield, draw a card.

All Slivers have "Sacrifice this permanent: Add {B}{B}."

{T}, Sacrifice Basal Thrull: Add {B}{B}.

Sacrifice Blood Pet: Add {B}.

Sacrifice Blood Vassal: Add {B}{B}.

Carrion Feeder can't block.

Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

As Choked Estuary enters the battlefield, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters the battlefield tapped.

{T}: Add {U} or {B}.

Creeping Tar Pit enters the battlefield tapped.

{T}: Add {U} or {B}.

{1}{U}{B}: Creeping Tar Pit becomes a 3/2 blue and black Elemental creature until end of turn and can't be blocked this turn. It's still a land.

Flying

Whenever you cycle or discard another card, scry 1.

Cycling {U} ({U}, Discard this card: Draw a card.)

Darkslick Shores enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {U} or {B}.

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Sacrifice a creature: Regenerate Dimir House Guard.

Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

When Disciple of Bolas enters the battlefield, sacrifice another creature. You gain X life and draw X cards, where X is that creature's power.

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

({T}: Add {U} or {B}.)

Fetid Pools enters the battlefield tapped.

Cycling {2} ({2}, Discard this card: Draw a card.)

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

{1}{B}, Sacrifice another creature: Put two +1/+1 counters on Flesh Carver.

When Flesh Carver dies, create an X/X black Horror creature token, where X is Flesh Carver's power.

Sacrifice Hapless Researcher: Draw a card, then discard a card.

Whenever you cycle or discard another card, Horror of the Broken Lands gets +2/+1 until end of turn.

Cycling {B} ({B}, Discard this card: Draw a card.)

Exile Ill-Gotten Gains. Each player discards their hand, then returns up to three cards from their graveyard to their hand.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Flying

When Mulldrifter enters the battlefield, draw two cards.

Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Flying

When Nevermaker leaves the battlefield, put target nonland permanent on top of its owner's library.

Evoke {3}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Flash

Flying

Cycling {2}{U} ({2}{U}, Discard this card: Draw a card.)

When you cycle Nimble Obstructionist, counter target activated or triggered ability you don't control.

Discard a card, Sacrifice Overeager Apprentice: Add {B}{B}{B}.

Pack Rat's power and toughness are each equal to the number of Rats you control.

{2}{B}, Discard a card: Create a token that's a copy of Pack Rat.

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

River Serpent can't attack unless there are five or more cards in your graveyard.

Cycling {U} ({U}, Discard this card: Draw a card.)

{2}{B}, Sacrifice a creature: Create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Sacrifice three Treasures: Draw a card.

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

When Shriekmaw enters the battlefield, destroy target nonartifact, nonblack creature.

Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Flying

Discard a card: Add {B}.

{T}, Sacrifice a black or artifact creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Cycling {U} ({U}, Discard this card: Draw a card.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

Temple of Deceit enters the battlefield tapped.

When Temple of Deceit enters the battlefield, scry 1.

{T}: Add {U} or {B}.

Flying

Whenever Thief of Sanity deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast it.

Cumulative upkeep {1}{B} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

At the beginning of each upkeep, if Tombstone Stairwell is on the battlefield, each player creates a 2/2 black Zombie creature token with haste named Tombspawn for each creature card in their graveyard.

At the beginning of each end step or when Tombstone Stairwell leaves the battlefield, destroy all tokens created with Tombstone Stairwell. They can't be regenerated.

{B}: Regenerate Twisted Abomination.

Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

{1}{B}, Discard a card: Return Undead Gladiator from your graveyard to your hand. Activate only during your upkeep.

Cycling {1}{B} ({1}{B}, Discard this card: Draw a card.)

First strike

Sacrifice Vampire Hexmage: Remove all counters from target permanent.

Flying

Cycling {U} ({U}, Discard this card: Draw a card.)

When you cycle Windcaller Aven, target creature gains flying until end of turn.