Whenever Carrion Wurm attacks or blocks, any player may exile three cards from their graveyard. If a player does, Carrion Wurm assigns no combat damage this turn.

Haste

Threshold — As long as seven or more cards are in your graveyard, Centaur Chieftain has “When Centaur Chieftain enters the battlefield, creatures you control get +1/+1 and gain trample until end of turn.”

Trample

{G}, Discard a card: Regenerate Centaur Veteran.

Whenever Cephalid Aristocrat becomes the target of a spell or ability, mill two cards.

Whenever Cephalid Illusionist becomes the target of a spell or ability, mill three cards.

{2}{U}, {T}: Prevent all combat damage that would be dealt to and dealt by target creature you control this turn.

Threshold — As long as seven or more cards are in your graveyard, Cephalid Sage has “When Cephalid Sage enters the battlefield, draw three cards, then discard two cards.”

Sacrifice Cephalid Snitch: Target creature loses protection from black until end of turn.

At the beginning of your upkeep, put a shred counter on Cephalid Vandal. Then mill a card for each shred counter on Cephalid Vandal.

All Nightmares get +1/+1.

{B}{B}{B}, Pay 3 life: Put target creature card from a graveyard onto the battlefield under your control. That creature is black and is a Nightmare in addition to its other creature types.

When Chainer, Dementia Master leaves the battlefield, exile all Nightmares.

Target player sacrifices a creature.

Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Return target creature and target land to their owners’ hands.

Counter target spell unless its controller pays {1} for each card in your graveyard.

Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Destroy all enchantments.

Threshold — If seven or more cards are in your graveyard, instead destroy all enchantments, then return all cards in your graveyard destroyed this way to the battlefield.

{1}{U}, Discard a card: Draw a card.

{1}{U}, Sacrifice Compulsion: Draw a card.

Enchant green or white creature

Enchanted creature has “At the beginning of your upkeep, sacrifice this creature unless you discard a card.”

Enchant creature

Enchanted creature gets +1/+0.

Sacrifice Crackling Club: It deals 1 damage to target creature.

When Crazed Firecat enters the battlefield, flip a coin until you lose a flip. Put a +1/+1 counter on Crazed Firecat for each flip you won.

Target creature gets -2/-2 until end of turn.

Flashback—{1}{B}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

At the beginning of your upkeep, you lose 1 life.

At the beginning of your upkeep, you may return target creature card from your graveyard to the battlefield. That creature gains haste until end of turn. Exile it at the beginning of the next end step.

Target player draws two cards.

Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)