Contagion Engine

When Contagion Engine enters, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Persist

Return target nonlegendary creature card from your graveyard to the battlefield with a -1/-1 counter on it.

Ruthless Sniper

Whenever you cycle or discard a card, you may pay {1}. If you do, put a -1/-1 counter on target creature.

Night's Whisper

Skeleton Ship

When you control no Islands, sacrifice Skeleton Ship.
{T}: Put a -1/-1 counter on target creature.

Swamp

Chisei, Heart of Oceans

Flying
At the beginning of your upkeep, sacrifice Chisei, Heart of Oceans unless you remove a counter from a permanent you control.

Necroskitter

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls with a -1/-1 counter on it dies, you may return that card to the battlefield under your control.

Casualties of War

Choose one or more —
• Destroy target artifact.
• Destroy target creature.
• Destroy target enchantment.
• Destroy target land.
• Destroy target planeswalker.

Crumbling Ashes

At the beginning of your upkeep, destroy target creature with a -1/-1 counter on it.

Dimir Signet

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on Devoted Druid: Untap Devoted Druid.

Dig Through Time

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Obelisk Spider

Reach
Whenever Obelisk Spider deals combat damage to a creature, put a -1/-1 counter on that creature.
Whenever you put one or more -1/-1 counters on a creature, each opponent loses 1 life and you gain 1 life.

Banewhip Punisher

When Banewhip Punisher enters, you may put a -1/-1 counter on target creature.
{B}, Sacrifice Banewhip Punisher: Destroy target creature that has a -1/-1 counter on it.

Sadistic Obsession

Enchant creature
Enchanted creature has "{B}, {T}: Put a -1/-1 counter on target creature."

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Skinrender

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

Liliana, Death Wielder

+2: Put a -1/-1 counter on up to one target creature.
−3: Destroy target creature with a -1/-1 counter on it.
−10: Return all creature cards from your graveyard to the battlefield.

Lethal Sting

As an additional cost to cast this spell, put a -1/-1 counter on a creature you control.
Destroy target creature.

Volrath, the Shapestealer

At the beginning of combat on your turn, put a -1/-1 counter on up to one target creature.
{1}: Until your next turn, Volrath, the Shapestealer becomes a copy of target creature with a counter on it, except it's 7/5 and it has this ability.

Midnight Banshee

Wither (This deals damage to creatures in the form of -1/-1 counters.)
At the beginning of your upkeep, put a -1/-1 counter on each nonblack creature.

Phyrexian Crusader

First strike, protection from red and from white
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Soul Diviner

{T}, Remove a counter from an artifact, creature, land, or planeswalker you control: Draw a card.

Grasping Dunes

{T}: Add {C}.
{1}, {T}, Sacrifice Grasping Dunes: Put a -1/-1 counter on target creature. Activate only as a sorcery.

Paradise Mantle

Equipped creature has "{T}: Add one mana of any color."
Equip {1}

Liliana of the Veil

+1: Each player discards a card.
−2: Target player sacrifices a creature.
−6: Separate all permanents target player controls into two piles. That player sacrifices all permanents in the pile of their choice.

Scarscale Ritual

As an additional cost to cast this spell, put a -1/-1 counter on a creature you control.
Draw two cards.

Splendid Agony

Distribute two -1/-1 counters among one or two target creatures.

Fevered Convulsions

{2}{B}{B}: Put a -1/-1 counter on target creature.

Maelstrom Pulse

Destroy target nonland permanent and all other permanents with the same name as that permanent.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Quillspike

{B/G}, Remove a -1/-1 counter from a creature you control: Quillspike gets +3/+3 until end of turn.

Golgari Signet

Hapatra, Vizier of Poisons

Whenever Hapatra, Vizier of Poisons deals combat damage to a player, you may put a -1/-1 counter on target creature.
Whenever you put one or more -1/-1 counters on a creature, create a 1/1 green Snake creature token with deathtouch.

Harbinger of Night

At the beginning of your upkeep, put a -1/-1 counter on each creature.

Glistening Oil

Enchant creature
Enchanted creature has infect.
At the beginning of your upkeep, put a -1/-1 counter on enchanted creature.
When Glistening Oil is put into a graveyard from the battlefield, return Glistening Oil to its owner's hand.

Sol Ring

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Sign in Blood

Target player draws two cards and loses 2 life.

Glen Elendra Archmage

Flying
{U}, Sacrifice Glen Elendra Archmage: Counter target noncreature spell.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Blowfly Infestation

Whenever a creature dies, if it had a -1/-1 counter on it, put a -1/-1 counter on target creature.

Incremental Blight

Put a -1/-1 counter on target creature, two -1/-1 counters on another target creature, and three -1/-1 counters on a third target creature.

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Leech Bonder

Leech Bonder enters with two -1/-1 counters on it.
{U}, {Q}: Move a counter from target creature onto a second target creature. ({Q} is the untap symbol.)

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Corrosive Mentor

Black creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)

Languish

All creatures get -4/-4 until end of turn.

Simic Signet

Gnarled Effigy

{4}, {T}: Put a -1/-1 counter on target creature.

Visara the Dreadful

Flying
{T}: Destroy target creature. It can't be regenerated.

Festering Mummy

When Festering Mummy dies, you may put a -1/-1 counter on target creature.

Wickerbough Elder

Wickerbough Elder enters with a -1/-1 counter on it.
{G}, Remove a -1/-1 counter from Wickerbough Elder: Destroy target artifact or enchantment.

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• Dread Presence deals 2 damage to any target and you gain 2 life.

Yawgmoth, Thran Physician

Protection from Humans
Pay 1 life, Sacrifice another creature: Put a -1/-1 counter on up to one target creature and draw a card.
{B}{B}, Discard a card: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Contagion Clasp

When Contagion Clasp enters, put a -1/-1 counter on target creature.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Carnifex Demon

Flying
Carnifex Demon enters with two -1/-1 counters on it.
{B}, Remove a -1/-1 counter from Carnifex Demon: Put a -1/-1 counter on each other creature.

Serrated Biskelion

{T}: Put a -1/-1 counter on Serrated Biskelion and a -1/-1 counter on target creature.

Dread

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever a creature deals damage to you, destroy it.
When Dread is put into a graveyard from anywhere, shuffle it into its owner's library.

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Soul Snuffers

When Soul Snuffers enters, put a -1/-1 counter on each creature.

Markov Dreadknight

Flying
{2}{B}, Discard a card: Put two +1/+1 counters on Markov Dreadknight.

Vedalken Anatomist

{2}{U}, {T}: Put a -1/-1 counter on target creature. You may tap or untap that creature.

Ifnir Deadlands

{T}: Add {C}.
{T}, Pay 1 life: Add {B}.
{2}{B}{B}, {T}, Sacrifice a Desert: Put two -1/-1 counters on target creature an opponent controls. Activate only as a sorcery.

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. Talisman of Resilience deals 1 damage to you.

Pyrrhic Revival

Each player returns each creature card from their graveyard to the battlefield with an additional -1/-1 counter on it.

Flourishing Defenses

Whenever a -1/-1 counter is put on a creature, you may create a 1/1 green Elf Warrior creature token.

Archfiend of Ifnir

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.)

Talisman of Curiosity

{T}: Add {C}.
{T}: Add {G} or {U}. Talisman of Curiosity deals 1 damage to you.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Nest of Scarabs

Whenever you put one or more -1/-1 counters on a creature, create that many 1/1 black Insect creature tokens.