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.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Nesting Grounds

{T}: Add {C}.
{1}, {T}: Move a counter from target permanent you control onto another target permanent. Activate only as a sorcery.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

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.

Black Sun's Zenith

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

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

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.

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Drown in Ichor

Target creature gets -4/-4 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Grasping Dunes

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

Crumbling Ashes

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

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

The Scorpion God

Whenever a creature with a -1/-1 counter on it dies, draw a card.
{1}{B}{R}: Put a -1/-1 counter on another target creature.
When The Scorpion God dies, return it to its owner's hand at the beginning of the next end step.

Xira Arien

Flying
{B}{R}{G}, {T}: Target player draws a card.

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

All Will Be One

Whenever you put one or more counters on a permanent or player, this enchantment deals that much damage to target opponent, creature an opponent controls, or planeswalker an opponent controls.

Liliana's Influence

Put a -1/-1 counter on each creature you don't control. You may search your library and/or graveyard for a card named Liliana, Death Wielder, reveal it, and put it into your hand. If you search your library this way, shuffle.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Blight Sickle

Equipped creature gets +1/+0 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
Equip {2}

Carnifex Demon

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

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.

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.

Reliquary Tower

Dusk Urchins

Whenever this creature attacks or blocks, put a -1/-1 counter on it.
When this creature dies, draw a card for each -1/-1 counter on it.

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.)

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Vhati il-Dal

{T}: Until end of turn, target creature has base power 1 or base toughness 1.

Stigma Lasher

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Whenever this creature deals damage to a player, that player can't gain life for the rest of the game.

Xira, the Golden Sting

Flying, haste
Whenever Xira attacks, put an egg counter on another target creature without an egg counter on it. When that creature dies, if it has an egg counter on it, draw a card and create a 1/1 black Insect creature token with flying.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Nest of Scarabs

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

Blowfly Infestation

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

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.

Wickerbough Elder

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

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.

Flourishing Defenses

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

Sol Ring

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.

Radiant Performer

Flash
When Radiant Performer enters, if you cast it from your hand, choose target spell or ability that targets only a single permanent or player. Copy that spell or ability for each other permanent or player the spell or ability could target. Each copy targets a different one of those permanents and players.

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.)

Sword of Truth and Justice

Equipped creature gets +2/+2 and has protection from white and from blue.
Whenever equipped creature deals combat damage to a player, put a +1/+1 counter on a creature you control, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Equip {2}

Serrated Arrows

This artifact enters with three arrowhead counters on it.
At the beginning of your upkeep, if there are no arrowhead counters on this artifact, sacrifice it.
{T}, Remove an arrowhead counter from this artifact: Put a -1/-1 counter on target creature.

Ashnod's Altar

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}