Disallow

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Serum Visions

Contentious Plan

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Draw a card.

Plague Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{T}: Add {C}.

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Graceful Adept

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Looter il-Kor

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Looter il-Kor deals damage to an opponent, draw a card, then discard a card.

Arm with Aether

Until end of turn, creatures you control gain "Whenever this creature deals damage to an opponent, you may return target creature that player controls to its owner's hand."

Reject Imperfection

Counter target spell. If that spell's mana value was 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Archaeomancer

When Archaeomancer enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Master of Waves

Protection from red
Elemental creatures you control get +1/+1.
When Master of Waves enters the battlefield, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Myriad Landscape

Myriad Landscape enters the battlefield tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Skyship Plunderer

Flying
Whenever Skyship Plunderer deals combat damage to a player, for each kind of counter on target permanent or player, give that permanent or player another counter of that kind.

Ichorclaw Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn.

Lightning Greaves

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

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Clear the Mind

Target player shuffles their graveyard into their library.
Draw a card.

Lonely Sandbar

Lonely Sandbar enters the battlefield tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Rogue's Passage

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

Silver Myr

Scroll Thief

Whenever Scroll Thief deals combat damage to a player, draw a card.

Nimble Obstructionist

Flash
Flying
Cycling {2}{U} ({2}{U}, Discard this card: Draw a card.)
When you cycle Nimble Obstructionist, counter target activated or triggered ability you don't control.

Library Larcenist

Whenever Library Larcenist attacks, draw a card.

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Kefnet's Monument

Blue creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.

Tekuthal, Inquiry Dominus

Flying
If you would proliferate, proliferate twice instead.
{1}{U/P}{U/P}, Remove three counters from among other artifacts, creatures, and planeswalkers you control: Put an indestructible counter on Tekuthal, Inquiry Dominus. ({U/P} can be paid with either {U} or 2 life.)

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Flux Channeler

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

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Reliquary Tower

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

Mocking Sprite

Flying
Instant and sorcery spells you cast cost {1} less to cast.

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.)

Mistblade Shinobi

Ninjutsu {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Mistblade Shinobi deals combat damage to a player, you may return target creature that player controls to its owner's hand.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Myr Convert

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
{T}, Pay 2 life: Add one mana of any color.

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Raven Guild Master

Whenever Raven Guild Master deals combat damage to a player, that player exiles the top ten cards of their library.
Morph {2}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Military Intelligence

Whenever you attack with two or more creatures, draw a card.

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Blighted Agent can't be blocked.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Viral Drake

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Phyrexian Digester

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Thieving Skydiver

Kicker {X}. X can't be 0. (You may pay an additional {X} as you cast this spell.)
Flying
When Thieving Skydiver enters the battlefield, if it was kicked, gain control of target artifact with mana value X or less. If that artifact is an Equipment, attach it to Thieving Skydiver.

Charix, the Raging Isle

Spells your opponents cast that target Charix, the Raging Isle cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Cephalid Constable

Whenever Cephalid Constable deals combat damage to a player, return up to that many target permanents that player controls to their owner's hand.

Thought Vessel

Dissipation Field

Whenever a permanent deals damage to you, return it to its owner's hand.

Aspirant's Ascent

Until end of turn, target creature gets +1/+3 and gains flying and toxic 1. (Players dealt combat damage by that creature also get a poison counter.)

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Unwind

Counter target noncreature spell. Untap up to three lands.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters the battlefield tapped unless you control three or more other Islands.
When Mystic Sanctuary enters the battlefield untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Tale's End

Counter target activated ability, triggered ability, or legendary spell.

Evolving Wilds

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

Island

Fuel for the Cause

Counter target spell, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Quietus Spike

Equipped creature has deathtouch.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Aetherize

Return all attacking creatures to their owner's hand.

Grazilaxx, Illithid Scholar

Whenever a creature you control becomes blocked, you may return it to its owner's hand.
Whenever one or more creatures you control deal combat damage to a player, draw a card.

Surrakar Spellblade

Whenever you cast an instant or sorcery spell, you may put a charge counter on Surrakar Spellblade.
Whenever Surrakar Spellblade deals combat damage to a player, you may draw X cards, where X is the number of charge counters on it.

Cephalid Facetaker

Cephalid Facetaker can't be blocked.
At the beginning of combat on your turn, you may have Cephalid Facetaker become a copy of another target creature until end of turn, except it's 1/4 and has "This creature can't be blocked."

Scytheclaw

Living weapon (When this Equipment enters the battlefield, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Necropede

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Necropede dies, you may put a -1/-1 counter on target creature.

Back to Basics

Nonbasic lands don't untap during their controllers' untap steps.

Guildpact Informant

Flying
Whenever Guildpact Informant deals combat damage to a player or planeswalker, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Castle Vantress

Castle Vantress enters the battlefield tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Distorted Curiosity

Corrupted — This spell costs {2} less to cast if an opponent has three or more poison counters.
Draw two cards.

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Unsummon

Return target creature to its owner's hand.

Sol Ring

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Halimar Depths

Halimar Depths enters the battlefield tapped.
When Halimar Depths enters the battlefield, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Dune Mover

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Dune Mover enters the battlefield, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Riptide Pilferer

Whenever Riptide Pilferer deals combat damage to a player, that player discards a card.
Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)