Have

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.

Foreboding Ruins

As this land enters, you may reveal a Swamp or Mountain card from your hand. If you don't, this land enters tapped.
{T}: Add {B} or {R}.

Twisted Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle.
Cycling {B}{R}{G} ({B}{R}{G}, Discard this card: Draw a card.)

Rootbound Crag

This land enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Skinrender

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

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Getting

Soul-Scar Mage

Prowess
If a source you control would deal noncombat damage to a creature an opponent controls, put that many -1/-1 counters on that creature instead.

Molten Duplication

Create a token that's a copy of target artifact or creature you control, except it's an artifact in addition to its other types. It gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Blooming Marsh

This land enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {G}.

Carrion Feeder

This creature can't block.
Sacrifice a creature: Put a +1/+1 counter on this creature.

Goblin Bombardment

Sacrifice a creature: This enchantment deals 1 damage to any target.

Dark Petition

Search your library for a card, put that card into your hand, then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, add {B}{B}{B}.

Don't Have

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.)

Persistent Constrictor

At the beginning of each opponent's upkeep, they lose 1 life and you put a -1/-1 counter on up to one target creature they control.
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.)

Natural Affinity

All lands become 2/2 creatures until end of turn. They're still lands.

Massacre Girl, Known Killer

Menace
Creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls dies, if its toughness was less than 1, draw a card.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Essence Warden

Whenever another creature enters, you gain 1 life.

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with this creature's toughness.

out?

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Contagion Engine

When this artifact 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.)

Harmonize

Morselhoarder

This creature enters with two -1/-1 counters on it.
Remove a -1/-1 counter from this creature: Add one mana of any color.

Rishkar, Peema Renegade

When Rishkar enters, put a +1/+1 counter on each of up to two target creatures.
Each creature you control with a counter on it has "{T}: Add {G}."

Kulrath Knight

Flying
Wither (This deals damage to creatures in the form of -1/-1 counters.)
Creatures your opponents control with counters on them can't attack or block.

Vernal Fen

({T}: Add {B} or {G}.)
This land enters tapped unless you control two or more basic lands.

Old-Growth Grove

This land enters tapped.
{T}: Add {B} or {G}.

Revitalizing Repast

Put a +1/+1 counter on target creature. It gains indestructible until end of turn.

Revitalizing Repast // Old-Growth Grove

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Deathsprout

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Chord of Calling

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Hapatra's Mark

Target creature you control gains hexproof until end of turn. Remove all -1/-1 counters from it. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Blackcleave Cliffs

This land enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {R}.

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Puppeteer Clique

Flying
When this creature enters, put target creature card from an opponent's graveyard onto the battlefield under your control. It gains haste. At the beginning of your next end step, exile it.
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.)

Woodland Cemetery

This land enters tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Gruul Turf

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Grumgully, the Generous

Each other non-Human creature you control enters with an additional +1/+1 counter on it.

Cinder Strike

As an additional cost to cast this spell, you may blight 1. (You may put a -1/-1 counter on a creature you control.)
Cinder Strike deals 2 damage to target creature. It deals 4 damage to that creature instead if this spell's additional cost was paid.

Chimil, the Inner Sun

Spells you control can't be countered.
At the beginning of your end step, discover 5. (Exile cards from the top of your library until you exile a nonland card with mana value 5 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Rockfall Vale

This land enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Unnatural Restoration

Return target permanent card from your graveyard to your hand. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Blazemire Verge

{T}: Add {B}.
{T}: Add {R}. Activate only if you control a Swamp or a Mountain.

Sinister Gnarlbark

At the beginning of your end step, draw a card and blight 1. (Put a -1/-1 counter on a creature you control.)

Everlasting Torment

Players can't gain life.
Damage can't be prevented.
All damage is dealt as though its source had wither. (A source with wither deals damage to creatures in the form of -1/-1 counters.)

Heat Shimmer

Create a token that's a copy of target creature, except it has haste and "At the beginning of the end step, exile this token."

Savage Lands

This land enters tapped.
{T}: Add {B}, {R}, or {G}.

Underworld Breach

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)
At the beginning of the end step, sacrifice this enchantment.

Puca's Covenant

Whenever a creature you control with a counter on it dies, you may return another target permanent card with mana value less than or equal to the number of counters on that creature from your graveyard to your hand. Do this only once each turn.

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.

Hapatra, Vizier of Poisons

Whenever Hapatra 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.

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Thirsting Roots

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Painful Truths

Converge — You draw X cards and lose X life, where X is the number of colors of mana spent to cast this spell.

Contagion Clasp

When this artifact 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.)

Twitching Doll

{T}: Add one mana of any color. Put a nest counter on this creature.
{T}, Sacrifice this creature: Create a 2/2 green Spider creature token with reach for each counter on this creature. Activate only as a sorcery.

Stomping Ground

({T}: Add {R} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

High Perfect Morcant

Whenever High Perfect Morcant or another Elf you control enters, each opponent blights 1. (They each put a -1/-1 counter on a creature they control.)
Tap three untapped Elves you control: Proliferate. Activate only as a sorcery. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Altar of Dementia

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

Riveteers Overlook

When this land enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Sudden Spoiling

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

Soul Immolation

As an additional cost to cast this spell, blight X. X can't be greater than the greatest toughness among creatures you control. (Put X -1/-1 counters on a creature you control.)
Soul Immolation deals X damage to each opponent and each creature they control.

Village Pillagers

Wither (This deals damage to creatures in the form of -1/-1 counters.)
When this creature enters, it deals 1 damage to each creature your opponents control.
Whenever a creature an opponent controls with a counter on it dies, you create a tapped Treasure token.

Fallen Ideal

Enchant creature
Enchanted creature has flying and "Sacrifice a creature: This creature gets +2/+1 until end of turn."
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.

Delighted Halfling

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell, and that spell can't be countered.

Viridian Emissary

When this creature dies, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Grim Affliction

Put a -1/-1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Obelisk Spider

Reach
Whenever this creature 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.

Cauldron of Souls

{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it 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.)

Sanguinary Priest

Lifelink
Blood Chalice — Whenever another creature you control dies, this creature deals 1 damage to any target.

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Decimator Beetle

When this creature enters, put a -1/-1 counter on target creature you control.
Whenever this creature attacks, remove a -1/-1 counter from target creature you control and put a -1/-1 counter on up to one target creature defending player controls.

Mountain

Swamp

Channeler Initiate

When this creature enters, put three -1/-1 counters on target creature you control.
{T}, Remove a -1/-1 counter from this creature: Add one mana of any color.

Auntie Ool, Cursewretch

Ward—Blight 2. (To blight 2, a player puts two -1/-1 counters on a creature they control.)
Whenever one or more -1/-1 counters are put on a creature, draw a card if you control that creature. If you don't control it, its controller loses 1 life.

Terramorphic Expanse

Spitting Dilophosaurus

Whenever this creature enters or attacks, put a -1/-1 counter on up to one target creature.
Creatures your opponents control with -1/-1 counters on them can't block.

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.

Dread Tiller

When this creature enters, put a -1/-1 counter on target creature.
Whenever a creature with a -1/-1 counter on it dies, you may put a land card from your hand or graveyard onto the battlefield tapped.

Elvish Harbinger

When this creature enters, you may search your library for an Elf card, reveal it, then shuffle and put that card on top.
{T}: Add one mana of any color.

Cinderhaze Wretch

{T}: Target player discards a card. Activate only during your turn.
Put a -1/-1 counter on this creature: Untap this creature.

Oft-Nabbed Goat

{1}: Draw a card. Gain control of this creature and put a -1/-1 counter on it. Only your opponents may activate this ability and only as a sorcery.
When this creature dies, if it had one or more -1/-1 counters on it, its owner draws that many cards and each other player loses that much life.

Rakdos Carnarium

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Atomize

Destroy target nonland permanent. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Terminate

Destroy target creature. It can't be regenerated.

Arcane Signet

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

Nowhere to Run

Flash
When this enchantment enters, target creature an opponent controls gets -3/-3 until end of turn.
Creatures your opponents control can be the targets of spells and abilities as though they didn't have hexproof. Ward abilities of those creatures don't trigger.

Flourishing Defenses

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

Wickersmith's Tools

Whenever one or more -1/-1 counters are put on a creature, put a charge counter on this artifact.
{T}: Add one mana of any color.
{5}, {T}, Sacrifice this artifact: Create X tapped 2/2 colorless Scarecrow artifact creature tokens, where X is the number of charge counters on this artifact.

Umbral Collar Zealot

Sacrifice another creature or artifact: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Canyon Slough

({T}: Add {B} or {R}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.)

Marvin, Murderous Mimic

Marvin has all activated abilities of creatures you control that don't have the same name as this creature.

Serrated Biskelion

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