Necrosynthesis

Enchant creature
Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature."
When enchanted creature dies, look at the top X cards of your library, where X is its power. Put one of those cards into your hand and the rest on the bottom of your library in a random order.

Eyeblight's Ending

Rise from the Grave

Put target creature card from a graveyard onto the battlefield under your control. That creature is a black Zombie in addition to its other colors and types.

Dreadhound

When Dreadhound enters, mill three cards. (Put the top three cards of your library into your graveyard.)
Whenever a creature dies or a creature card is put into a graveyard from a library, each opponent loses 1 life.

Reckoner Shakedown

Target opponent reveals their hand. You may choose a nonland card from it. If you do, that player discards that card. If you don't, put two +1/+1 counters on a creature or Vehicle you control.

Eaten Alive

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Exile target creature or planeswalker.

Circuit Mender

When Circuit Mender enters, you gain 2 life.
When Circuit Mender leaves the battlefield, draw a card.

Baneclaw Marauder

Whenever Baneclaw Marauder becomes blocked, each creature blocking it gets -1/-1 until end of turn.
Whenever a creature blocking Baneclaw Marauder dies, that creature's controller loses 1 life.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Baneblade Scoundrel

Whenever Baneblade Scoundrel becomes blocked, each creature blocking it gets -1/-1 until end of turn.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Baneblade Scoundrel // Baneclaw Marauder

Slaughter Specialist

When Slaughter Specialist enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on Slaughter Specialist.

Crawl from the Cellar

Return target creature card from your graveyard to your hand. Put a +1/+1 counter on up to one target Zombie you control.
Flashback {3}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Extinguish the Light

Destroy target creature or planeswalker. If its mana value was 3 or less, you gain 3 life.

Tragic Fall

Target creature gets -3/-3 until end of turn.
Hellbent — That creature gets -13/-13 until end of turn instead if you have no cards in hand.

Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Balustrade Spy

Flying
When Balustrade Spy enters, target player reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Necrogoyf

Necrogoyf's power is equal to the number of creature cards in all graveyards.
At the beginning of each player's upkeep, that player discards a card.
Madness {1}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Witch's Cauldron

{1}{B}, {T}, Sacrifice a creature: You gain 1 life and draw a card.

Dockside Chef

{1}{B}, Sacrifice an artifact or creature: Draw a card.

Covetous Geist

Flying, deathtouch
If Covetous Geist would be put into a graveyard from anywhere, exile it instead.

Covert Cutpurse

When Covert Cutpurse enters, destroy target creature you don't control that was dealt damage this turn.
Disturb {4}{B} (You may cast this card from your graveyard transformed for its disturb cost.)

Covert Cutpurse // Covetous Geist

Massacre Girl

Menace
When Massacre Girl enters, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Debt to the Kami

Choose one —
• Target opponent exiles a creature they control.
• Target opponent exiles an enchantment they control.

World-Weary

Enchant creature
Enchanted creature gets -4/-4.
Basic landcycling {1}{B} ({1}{B}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Memory of Toshiro

{T}, Pay 1 life: Add {B}. Spend this mana only to cast an instant or sorcery spell.

Life of Toshiro Umezawa

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Choose one —
• Target creature gets +2/+2 until end of turn.
• Target creature gets -1/-1 until end of turn.
• You gain 2 life.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Life of Toshiro Umezawa // Memory of Toshiro

Vermin Gorger

{T}, Sacrifice another creature: Each opponent loses 2 life and you gain 2 life.

Animus of Night's Reach

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Animus of Night's Reach attacks, it gets +X/+0 until end of turn, where X is the number of creature cards in defending player's graveyard.

The Long Reach of Night

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Each opponent sacrifices a creature of their choice unless they discard a card.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Long Reach of Night // Animus of Night's Reach

Honored Heirloom

{T}: Add one mana of any color.
{2}, {T}: Exile target card from a graveyard.

Bladebrand

Target creature gains deathtouch until end of turn.
Draw a card.

Strangling Grasp

Enchant creature or planeswalker an opponent controls
At the beginning of your upkeep, enchanted permanent's controller sacrifices a nonland permanent of their choice, then that player loses 1 life.

Vengeful Strangler

Vengeful Strangler can't block.
When Vengeful Strangler dies, return it to the battlefield transformed under your control attached to target creature or planeswalker an opponent controls.

Vengeful Strangler // Strangling Grasp

Loathsome Curator

Exploit (When this creature enters, you may sacrifice a creature.)
Menace
When Loathsome Curator exploits a creature, destroy target creature you don't control with mana value 3 or less.

Novice Occultist

When Novice Occultist dies, you draw a card and you lose 1 life.

Manalith

Bottle Golems

Trample
When Bottle Golems dies, you gain life equal to its power.

Archfiend of Sorrows

Flying
When Archfiend of Sorrows enters, creatures your opponents control get -2/-2 until end of turn.
Unearth {3}{B}{B} ({3}{B}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Malicious Invader

Flying
Malicious Invader gets +2/+0 as long as an opponent controls a Human.

Innocent Traveler

At the beginning of your upkeep, any opponent may sacrifice a creature of their choice. If no one does, transform Innocent Traveler.

Innocent Traveler // Malicious Invader

Ormendahl, the Corrupter

Flying, trample, lifelink
Sacrifice another creature: Draw a card.

Jerren, Corrupted Bishop

Whenever Jerren, Corrupted Bishop enters or another nontoken Human you control dies, you lose 1 life and create a 1/1 white Human creature token.
{2}: Target Human you control gains lifelink until end of turn.
At the beginning of your end step, if you have exactly 13 life, you may pay {4}{B}{B}. If you do, transform Jerren.

Jerren, Corrupted Bishop // Ormendahl, the Corrupter

Depraved Harvester

Desperate Farmer

Lifelink
When another creature you control dies, transform Desperate Farmer.

Desperate Farmer // Depraved Harvester

Seekers' Squire

When Seekers' Squire enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

You Are Already Dead

Destroy target creature that was dealt damage this turn.
Draw a card.

Phyrexian Rager

When Phyrexian Rager enters, you draw a card and you lose 1 life.

Zof Bloodbog

Zof Bloodbog enters tapped.
{T}: Add {B}.

Zof Consumption

Each opponent loses 4 life and you gain 4 life.

Zof Consumption // Zof Bloodbog

Tormod's Cryptkeeper

Vigilance
{T}, Sacrifice Tormod's Cryptkeeper: Exile target player's graveyard.

Corpse Churn

Mill three cards, then you may return a creature card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Leech Gauntlet

Lifelink
Equipped creature has lifelink.
Reconfigure {4} ({4}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Awoken Demon

Ecstatic Awakener

{2}{B}, Sacrifice another creature: Draw a card, then transform Ecstatic Awakener. Activate only once each turn.

Ecstatic Awakener // Awoken Demon

Defenestrate

Nezumi Road Captain

Menace
Vehicles you control have menace. (They can't be blocked except by two or more creatures.)

Okiba Reckoner Raid

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Each opponent loses 1 life and you gain 1 life.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Okiba Reckoner Raid // Nezumi Road Captain

Gavony Unhallowed

Whenever another creature you control dies, put a +1/+1 counter on Gavony Unhallowed.

Severed Strands

As an additional cost to cast this spell, sacrifice a creature.
You gain life equal to the sacrificed creature's toughness. Destroy target creature an opponent controls.

Vampire Sovereign

Flying
When Vampire Sovereign enters, target opponent loses 3 life and you gain 3 life.

Liliana's Elite

Liliana's Elite gets +1/+1 for each creature card in your graveyard.

Underworld Hermit

When Underworld Hermit enters, create a number of 1/1 green Squirrel creature tokens equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Clawing Torment

Enchant artifact or creature
As long as enchanted permanent is a creature, it gets -1/-1 and can't block.
Enchanted permanent has "At the beginning of your upkeep, you lose 1 life."

Persistent Specimen

{2}{B}: Return Persistent Specimen from your graveyard to the battlefield tapped.

Sanitarium Skeleton

{2}{B}: Return Sanitarium Skeleton from your graveyard to your hand.

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on Bloodflow Connoisseur.

Return to Action

Until end of turn, target creature gets +1/+0 and gains lifelink and "When this creature dies, return it to the battlefield tapped under its owner's control."

Swamp

Skinrender

When Skinrender enters, put three -1/-1 counters on target creature.

Blood Pact

Target player draws two cards and loses 2 life.

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 Bone Shredder enters, destroy target nonartifact, nonblack creature.

Rotten Reunion

Exile up to one target card from a graveyard. Create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

No Way Out

Target opponent discards two cards. You create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)