Stromgald Cabal

{T}, Pay 1 life: Counter target white spell.

Green Slime

Flash
When Green Slime enters, counter target activated or triggered ability from an artifact or enchantment source. If a permanent's ability is countered this way, destroy that permanent.
Foretell {G} (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.)

Equinox

Enchant land
Enchanted land has "{T}: Counter target spell if it would destroy a land you control."

Warping Wail

({C} represents colorless mana.)
Choose one —
• Exile target creature with power or toughness 1 or less.
• Counter target sorcery spell.
• Create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."

Rust

Counter target activated ability from an artifact source. (Mana abilities can't be targeted.)

Chancellor of the Annex

You may reveal this card from your opening hand. If you do, when each opponent casts their first spell of the game, counter that spell unless that player pays {1}.
Flying
Whenever an opponent casts a spell, counter it unless that player pays {1}.

Brown Ouphe

{1}{G}, {T}: Counter target activated ability from an artifact source. (Mana abilities can't be targeted.)

Dissonant Wave

Counter target activated or triggered ability from a noncreature source. (Then exile this card. You may cast the creature later from exile.)

Emerald Dragon

Emerald Dragon // Dissonant Wave

Vial Smasher the Fierce

Whenever you cast your first spell each turn, choose an opponent at random. Vial Smasher the Fierce deals damage equal to that spell's mana value to that player or a planeswalker that player controls.
Partner (You can have two commanders if both have partner.)

Nullstone Gargoyle

Flying
Whenever the first noncreature spell of a turn is cast, counter that spell.

Rebuff the Wicked

Counter target spell that targets a permanent you control.

Exotic Orchard

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

Guttural Response

Verdant Command

Choose two —
• Target player creates two tapped 1/1 green Squirrel creature tokens.
• Counter target loyalty ability of a planeswalker.
• Exile target card from a graveyard.
• Target player gains 3 life.

Forest

Sundial of the Infinite

{1}, {T}: End the turn. Activate only during your turn. (Exile all spells and abilities from the stack. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Solemn Simulacrum

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

Null Brooch

{2}, {T}, Discard your hand: Counter target noncreature spell.

Kozilek, the Great Distortion

When you cast this spell, if you have fewer than seven cards in hand, draw cards equal to the difference.
Menace
Discard a card with mana value X: Counter target spell with mana value X.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Dawn Charm

Choose one —
• Prevent all combat damage that would be dealt this turn.
• Regenerate target creature.
• Counter target spell that targets you.

Arcane Signet

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

Heroes' Podium

Each legendary creature you control gets +1/+1 for each other legendary creature you control.
{X}, {T}: Look at the top X cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Not of This World

Counter target spell or ability that targets a permanent you control.
This spell costs {7} less to cast if it targets a spell or ability that targets a creature you control with power 7 or greater.

Chalice of the Void

Chalice of the Void enters with X charge counters on it.
Whenever a player casts a spell with mana value equal to the number of charge counters on Chalice of the Void, counter that spell.

Evolving Wilds

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

Lifeforce

Glorious End

End the turn. (Exile all spells and abilities from the stack, including this card. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)
At the beginning of your next end step, you lose the game.

Terramorphic Expanse

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

Dash Hopes

When you cast this spell, any player may pay 5 life. If a player does, counter Dash Hopes.
Counter target spell.

Ring of Immortals

{3}, {T}: Counter target instant or Aura spell that targets a permanent you control.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Rob the Hoard

Return target artifact, enchantment, or legendary card from your graveyard to your hand. (Then exile this card. You may cast the creature later from exile.)

Crystal Dragon

Crystal Dragon // Rob the Hoard

Savage Lands

Savage Lands enters tapped.
{T}: Add {B}, {R}, or {G}.

Artifact Blast

Shell of the Last Kappa

{3}, {T}: Exile target instant or sorcery spell that targets you. (The spell has no effect.)
{3}, {T}, Sacrifice Shell of the Last Kappa: You may cast a spell from among cards exiled with Shell of the Last Kappa without paying its mana cost.

Piru, the Volatile

Flying, lifelink
At the beginning of your upkeep, sacrifice Piru, the Volatile unless you pay {R}{W}{B}.
When Piru dies, it deals 7 damage to each nonlegendary creature.

Bind

Counter target activated ability. (Mana abilities can't be targeted.)
Draw a card.

Tibalt's Trickery

Counter target spell. Choose 1, 2, or 3 at random. Its controller mills that many cards, then exiles cards from the top of their library until they exile a nonland card with a different name than that spell. They may cast that card without paying its mana cost. Then they put the exiled cards on the bottom of their library in a random order.

Yoshimaru, Ever Faithful

Whenever another legendary permanent you control enters, put a +1/+1 counter on Yoshimaru, Ever Faithful.
Partner (You can have two commanders if both have partner.)

Burnout

Counter target instant spell if it's blue.
Draw a card at the beginning of the next turn's upkeep.

Plains

Tyrite Sanctum

{T}: Add {C}.
{2}, {T}: Target legendary creature becomes a God in addition to its other types. Put a +1/+1 counter on it.
{4}, {T}, Sacrifice Tyrite Sanctum: Put an indestructible counter on target God.

Ouphe Vandals

{G}, Sacrifice Ouphe Vandals: Counter target activated ability from an artifact source and destroy that artifact if it's on the battlefield. (Mana abilities can't be targeted.)

Sandsteppe Citadel

Sandsteppe Citadel enters tapped.
{T}: Add {W}, {B}, or {G}.

Farseek

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

Deathgrip

Order of the Sacred Torch

{T}, Pay 1 life: Counter target black spell.

Sidar Kondo of Jamuraa

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
Creatures your opponents control without flying or reach can't block creatures with power 2 or less.
Partner (You can have two commanders if both have partner.)

Swamp

Illumination

Counter target artifact or enchantment spell. Its controller gains life equal to its mana value.

Amulet of Safekeeping

Whenever you become the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.
Creature tokens get -1/-0.

Unyaro Griffin

Flying
Sacrifice Unyaro Griffin: Counter target red instant or sorcery spell.

Mages' Contest

You and target spell's controller bid life. You start the bidding with a bid of 1. In turn order, each player may top the high bid. The bidding ends if the high bid stands. The high bidder loses life equal to the high bid. If you win the bidding, counter that spell.

Wild Ricochet

You may choose new targets for target instant or sorcery spell. Then copy that spell. You may choose new targets for the copy.

Withering Boon

As an additional cost to cast this spell, pay 3 life.
Counter target creature spell.

Molten Influence

Counter target instant or sorcery spell unless its controller has Molten Influence deal 4 damage to them.

Mountain

Frontline Medic

Battalion — Whenever Frontline Medic and at least two other creatures attack, creatures you control gain indestructible until end of turn.
Sacrifice Frontline Medic: Counter target spell with {X} in its mana cost unless its controller pays {3}.

Thrull Wizard

{1}{B}: Counter target black spell unless that spell's controller pays {B} or {3}.

Ornithopter of Paradise

Lapse of Certainty

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Avoid Fate

Counter target instant or Aura spell that targets a permanent you control.

Fellwar Stone

Nomad Outpost

Nomad Outpost enters tapped.
{T}: Add {R}, {W}, or {B}.

Planar Chaos

At the beginning of your upkeep, flip a coin. If you lose the flip, sacrifice Planar Chaos.
Whenever a player casts a spell, that player flips a coin. If they lose the flip, counter that spell.

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Mage's Attendant

When Mage's Attendant enters, create a 1/1 blue Wizard creature token with "{1}, Sacrifice this creature: Counter target noncreature spell unless its controller pays {1}."

Command Tower

Mana Tithe

Counter target spell unless its controller pays {1}.

Jungle Shrine

Jungle Shrine enters tapped.
{T}: Add {R}, {G}, or {W}.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

The Circle of Loyalty

This spell costs {1} less to cast for each Knight you control.
Creatures you control get +1/+1.
Whenever you cast a legendary spell, create a 2/2 white Knight creature token with vigilance.
{3}{W}, {T}: Create a 2/2 white Knight creature token with vigilance.

Chromatic Lantern

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