The Core

(Transforms from Matzalantli.)
Fathomless descent — {T}: Add X mana of any one color, where X is the number of permanent cards in your graveyard.

Matzalantli, the Great Door

{T}: Draw a card, then discard a card.
{4}, {T}: Transform Matzalantli, the Great Door. Activate only if there are four or more permanent types among cards in your graveyard. (Artifact, battle, creature, enchantment, land, and planeswalker are permanent types.)

Matzalantli, the Great Door // The Core

Go-Shintai of Hidden Cruelty

Deathtouch
At the beginning of your end step, you may pay {1}. When you do, destroy target creature with toughness X or less, where X is the number of Shrines you control.

Kuon's Essence

At the beginning of each player's upkeep, that player sacrifices a creature.

Kuon, Ogre Ascendant

At the beginning of the end step, if three or more creatures died this turn, flip Kuon, Ogre Ascendant.

Kuon, Ogre Ascendant // Kuon's Essence

Skull of Orm

{5}, {T}: Return target enchantment card from your graveyard to your hand.

Temple of Aclazotz

(Transforms from Arguel's Blood Fast.)
{T}: Add {B}.
{T}, Sacrifice a creature: You gain life equal to the sacrificed creature's toughness.

Arguel's Blood Fast

{1}{B}, Pay 2 life: Draw a card.
At the beginning of your upkeep, if you have 5 or less life, you may transform Arguel's Blood Fast.

Arguel's Blood Fast // Temple of Aclazotz

Night of Souls' Betrayal

Tymaret, Chosen from Death

Tymaret's toughness is equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
{1}{B}: Exile up to two target cards from graveyards. You gain 1 life for each creature card exiled this way.

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Lich-Knights' Conquest

Sacrifice any number of artifacts, enchantments, and/or tokens. Return that many creature cards from your graveyard to the battlefield.

Aphemia, the Cacophony

Flying
At the beginning of your end step, you may exile an enchantment card from your graveyard. If you do, create a 2/2 black Zombie creature token.

Extinguish All Hope

Warehouse Tabby

Whenever an enchantment you control is put into a graveyard from the battlefield, create a 1/1 black Rat creature token with "This creature can't block."
{1}{B}: Warehouse Tabby gains deathtouch until end of turn.

Kami of Terrible Secrets

When Kami of Terrible Secrets enters the battlefield, if you control an artifact and an enchantment, you draw a card and you gain 1 life.

Swamp

Sanctum of Stone Fangs

At the beginning of your precombat main phase, each opponent loses X life and you gain X life, where X is the number of Shrines you control.

Taken by Nightmares

Exile target creature. If you control an enchantment, scry 2.

Honden of Night's Reach

At the beginning of your upkeep, target opponent discards a card for each Shrine you control.