Mana Breach

Whenever a player casts a spell, that player returns a land they control to its owner's hand.

Abdel Adrian, Gorion's Ward

When Abdel Adrian, Gorion's Ward enters, exile any number of other nonland permanents you control until Abdel Adrian leaves the battlefield. Create a 1/1 white Soldier creature token for each permanent exiled this way.
Choose a Background (You can have a Background as a second commander.)

Talisman of Progress

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

Ghostly Prison

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Vryn Wingmare

Flying
Noncreature spells cost {1} more to cast.

Frozen Aether

Artifacts, creatures, and lands your opponents control enter tapped.

Skybridge Towers

Skybridge Towers enters tapped.
{T}: Add {W} or {U}.
{2}{W}{U}, {T}, Sacrifice Skybridge Towers: Draw a card.

Slow Motion

Enchant creature
At the beginning of the upkeep of enchanted creature's controller, that player sacrifices that creature unless they pay {2}.
When Slow Motion is put into a graveyard from the battlefield, return Slow Motion to its owner's hand.

Mnemonic Wall

Defender
When Mnemonic Wall enters, you may return target instant or sorcery card from your graveyard to your hand.

Oji, the Exquisite Blade

When Oji, the Exquisite Blade enters, you gain 2 life and scry 2.
Whenever you cast your second spell each turn, exile up to one target creature you control, then return it to the battlefield under its owner's control.

Generous Gift

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

Plains

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Spirited Companion

When Spirited Companion enters, draw a card.

Suppression Field

Activated abilities cost {2} more to activate unless they're mana abilities.

Aura of Silence

Artifact and enchantment spells your opponents cast cost {2} more to cast.
Sacrifice Aura of Silence: Destroy target artifact or enchantment.

Energy Flux

All artifacts have "At the beginning of your upkeep, sacrifice this artifact unless you pay {2}."

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Githzerai Monk

Flash
Flying
Psychic Defense — When Githzerai Monk enters, tap all creatures you don't control.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Obscura Storefront

When Obscura Storefront enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Rescuer Chwinga

Flash
Natural Shelter — When Rescuer Chwinga enters, you may return another permanent you control to its owner's hand.

Soulherder

Whenever a creature is exiled from the battlefield, put a +1/+1 counter on Soulherder.
At the beginning of your end step, you may exile another target creature you control, then return that card to the battlefield under its owner's control.

Rule of Law

Each player can't cast more than one spell each turn.

Juvenile Mist Dragon

Flying
Confounding Clouds — When Juvenile Mist Dragon enters, for each opponent, tap up to one target creature that player controls. Each of those creatures doesn't untap during its controller's next untap step.

Fade Away

For each creature, its controller sacrifices a permanent of their choice unless they pay {1}.

Azorius Signet

Reflector Mage

When Reflector Mage enters, return target creature an opponent controls to its owner's hand. That creature's owner can't cast spells with the same name as that creature until your next turn.

Dawnbringer Cleric

When Dawnbringer Cleric enters, choose one —
• Cure Wounds — You gain 2 life.
• Dispel Magic — Destroy target enchantment.
• Gentle Repose — Exile target card from a graveyard.

Sol Ring

Circuit Mender

When Circuit Mender enters, you gain 2 life.
When Circuit Mender leaves the battlefield, draw a card.

Rumor Gatherer

Alliance — Whenever another creature you control enters, scry 1. If this is the second time this ability has resolved this turn, draw a card instead.

Cloudblazer

Flying
When this creature enters, you gain 2 life and draw two cards.

Minimus Containment

Enchant nonland permanent
Enchanted permanent is a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color," and it loses all other abilities. (If it was a creature, it's no longer a creature.)

Disciple of the Sun

Lifelink
When Disciple of the Sun enters, return target permanent card with mana value 3 or less from your graveyard to your hand.

Far Traveler

Commander creatures you own have "At the beginning of your end step, exile up to one target tapped creature you control, then return it to the battlefield under its owner's control."

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Counterspell

Arcane Laboratory

Command Tower

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

Sphere of Safety

Creatures can't attack you or planeswalkers you control unless their controller pays {X} for each of those creatures, where X is the number of enchantments you control.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Displace

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Propaganda

Dream Tides

Creatures don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player may choose any number of tapped nongreen creatures they control and pay {2} for each creature chosen this way. If the player does, untap those creatures.

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Ninth Bridge Patrol

Whenever another creature you control leaves the battlefield, put a +1/+1 counter on Ninth Bridge Patrol.

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Alora, Merry Thief

Whenever you attack, up to one target attacking creature can't be blocked this turn. Return that creature to its owner's hand at the beginning of the next end step.
Choose a Background (You can have a Background as a second commander.)

Kismet

Mulldrifter

Flying
When Mulldrifter enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Flaming Fist Officer

Whenever another creature you control leaves the battlefield, put a +1/+1 counter on Flaming Fist Officer.

Rishadan Cutpurse

When Rishadan Cutpurse enters, each opponent sacrifices a permanent of their choice unless they pay {1}.

Rishadan Footpad

When Rishadan Footpad enters, each opponent sacrifices a permanent of their choice unless they pay {2}.

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Sky Diamond

War Tax

{X}{U}: This turn, creatures can't attack unless their controller pays {X} for each attacking creature they control.

Web of Inertia

At the beginning of combat on each opponent's turn, that player may exile a card from their graveyard. If the player doesn't, creatures they control can't attack you this turn.

Eidolon of Rhetoric

Peregrine Drake

Flying
When Peregrine Drake enters, untap up to five lands.

Arcane Signet

Archaeomancer

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

Darksteel Mutation

Enchant creature
Enchanted creature is an Insect artifact creature with base power and toughness 0/1 and has indestructible, and it loses all other abilities, card types, and creature types.

Island

Elite Guardmage

Flying
When Elite Guardmage enters, you gain 3 life and draw a card.

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Negate

Brokers Hideout

When Brokers Hideout enters, sacrifice it. When you do, search your library for a basic Forest, Plains, or Island card, put it onto the battlefield tapped, then shuffle and you gain 1 life.