Ishai, Ojutai Dragonspeaker

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Ishai, Ojutai Dragonspeaker.
Partner (You can have two commanders if both have partner.)

Forest

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.)

Abzan Skycaptain

Flying
When Abzan Skycaptain dies, bolster 2. (Choose a creature with the least toughness among creatures you control and put two +1/+1 counters on it.)

Arctic Aven

Flying
Arctic Aven gets +1/+1 as long as you control a Plains.
{W}: Arctic Aven gains lifelink until end of turn. (Damage dealt by this creature also causes you to gain that much life.)

Endless Detour

The owner of target spell, nonland permanent, or card in a graveyard puts it on the top or bottom of their library.

Swooping Protector

Flash
Flying
Swooping Protector enters the battlefield with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

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.)

Artificer's Assistant

Flying
Whenever you cast a historic spell, scry 1. (Artifacts, legendaries, and Sagas are historic. To scry 1, look at the top card of your library, then you may put that card on the bottom of your library.)

Aerie Mystics

Flying
{1}{G}{U}: Creatures you control gain shroud until end of turn. (They can't be the targets of spells or abilities.)

Gwaihir the Windlord

This spell costs {2} less to cast as long as you've drawn two or more cards this turn.
Flying, vigilance
Other Birds you control have vigilance.

Staff of Compleation

{T}, Pay 1 life: Destroy target permanent you own.
{T}, Pay 2 life: Add one mana of any color.
{T}, Pay 3 life: Proliferate.
{T}, Pay 4 life: Draw a card.
{5}: Untap Staff of Compleation.

Steady Progress

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

Battlefield Raptor

Sol Ring

Aven Courier

Flying
Whenever Aven Courier attacks, choose a counter on a permanent you control. Put a counter of that kind on target permanent you control if it doesn't have a counter of that kind on it.

Seaside Citadel

Seaside Citadel enters the battlefield tapped.
{T}: Add {G}, {W}, or {U}.

Plains

Spara's Headquarters

({T}: Add {G}, {W}, or {U}.)
Spara's Headquarters enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Brokers Ascendancy

At the beginning of your end step, put a +1/+1 counter on each creature you control and a loyalty counter on each planeswalker you control.

Eddytrail Hawk

Flying
When Eddytrail Hawk enters the battlefield, you get {E}{E} (two energy counters).
Whenever Eddytrail Hawk attacks, you may pay {E}. If you do, another target attacking creature gains flying until end of turn.

Soulcatcher

Flying
Whenever a creature with flying dies, put a +1/+1 counter on Soulcatcher.

Heron of Hope

Flying
If you would gain life, you gain that much life plus 1 instead.
{1}{W}: Heron of Hope gains lifelink until end of turn.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Aerial Extortionist

Flying
Whenever Aerial Extortionist enters the battlefield or deals combat damage to a player, exile up to one target nonland permanent. For as long as that card remains exiled, its owner may cast it.
Whenever another player casts a spell from anywhere other than their hand, draw a card.

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.)

Aether Hub

When Aether Hub enters the battlefield, you get {E} (an energy counter).
{T}: Add {C}.
{T}, Pay {E}: Add one mana of any color.

Stormwild Capridor

Flying
If noncombat damage would be dealt to Stormwild Capridor, prevent that damage. Put a +1/+1 counter on Stormwild Capridor for each 1 damage prevented this way.

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.)

Treva's Ruins

When Treva's Ruins enters the battlefield, sacrifice it unless you return a non-Lair land you control to its owner's hand.
{T}: Add {G}, {W}, or {U}.

Commander's Sphere

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

Courage in Crisis

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.)

Island

Aven Battle Priest

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Aven Battle Priest enters the battlefield, you gain 3 life.

Skyboon Evangelist

Flying
When Skyboon Evangelist enters the battlefield, support 6. (Put a +1/+1 counter on each of up to six other target creatures.)
Whenever a creature with a counter on it attacks one of your opponents, that creature gains flying until end of turn.

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.)

Command Tower

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

Flensing Raptor

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Flensing Raptor enters the battlefield, another target creature you control with toxic gets +1/+1 and gains flying until end of turn.

Derevi, Empyrial Tactician

Flying
Whenever Derevi, Empyrial Tactician enters the battlefield or a creature you control deals combat damage to a player, you may tap or untap target permanent.
{1}{G}{W}{U}: Put Derevi onto the battlefield from the command zone.

Inexorable Tide

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

Augury Owl

Flying
When Augury Owl enters the battlefield, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Curiosity Crafter

Flying
You have no maximum hand size.
Whenever a creature token you control deals combat damage to a player, draw a card.

Flurry of Wings

Create X 1/1 white Bird Soldier creature tokens with flying, where X is the number of attacking creatures.

Brokers Charm

Choose one —
• Target creature you control gets +1/+0 until end of turn. It deals damage equal to its power to target creature or planeswalker an opponent controls.
• Destroy target enchantment.
• Draw two cards.

Vivisurgeon's Insight

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

Aven Mindcensor

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

Vulpikeet

Mutate {2}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying
Whenever this creature mutates, put a +1/+1 counter on it.

Bant Charm

Choose one —
• Destroy target artifact.
• Put target creature on the bottom of its owner's library.
• Counter target instant spell.

Aven Surveyor

Flying
When Aven Surveyor enters the battlefield, choose one —
• Put a +1/+1 counter on Aven Surveyor.
• Return target creature to its owner's hand.

Healer's Hawk

Aven Tactician

Flying
When Aven Tactician enters the battlefield, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Healer's Flock

Carnivorous Canopy

Destroy target artifact, enchantment, or creature with flying. If that permanent'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.)

Smell Fear

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Target creature you control fights up to one target creature you don't control.

Aven of Enduring Hope

Flying
When Aven of Enduring Hope enters the battlefield, you gain 3 life.

Supply-Line Cranes

Flying
When Supply-Line Cranes enters the battlefield, put a +1/+1 counter on target creature.

Aetherstorm Roc

Flying
Whenever Aetherstorm Roc or another creature enters the battlefield under your control, you get {E} (an energy counter).
Whenever Aetherstorm Roc attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it and tap up to one target creature defending player controls.

The Goose Mother

Flying
The Goose Mother enters the battlefield with X +1/+1 counters on it.
When The Goose Mother enters the battlefield, create half X Food tokens, rounded up.
Whenever The Goose Mother attacks, you may sacrifice a Food. If you do, draw a card.

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Contagion Clasp

When Contagion Clasp enters the battlefield, 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.)

Aven Gagglemaster

Flying
When Aven Gagglemaster enters the battlefield, you gain 2 life for each creature you control with flying.

Wargate

Search your library for a permanent card with mana value X or less, put it onto the battlefield, then shuffle.

Colorful Feiyi Sparrow

Flying (This creature can't be blocked except by creatures with flying or reach.)

Contentious Plan

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.)

Clarion Ultimatum

Choose five permanents you control. For each of those permanents, you may search your library for a card with the same name as that permanent. Put those cards onto the battlefield tapped, then shuffle.

Aven Skirmisher

Birds of Paradise

Falco Spara, Pactweaver

Flying, trample
Falco Spara, Pactweaver enters the battlefield with a shield counter on it.
You may look at the top card of your library any time.
You may cast spells from the top of your library by removing a counter from a creature you control in addition to paying their other costs.

Brokers Confluence

Choose three. You may choose the same mode more than once.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
• Target creature phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)
• Counter target activated or triggered ability.

Tainted Observer

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever another creature enters the battlefield under your control, you may pay {2}. If you do, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Animal Sanctuary

{T}: Add {C}.
{2}, {T}: Put a +1/+1 counter on target Bird, Cat, Dog, Goat, Ox, or Snake.

Aven Mimeomancer

Flying
At the beginning of your upkeep, you may put a feather counter on target creature. If you do, that creature has base power and toughness 3/1 and has flying for as long as it has a feather counter on it.

Unbounded Potential

Choose one —
• Put a +1/+1 counter on each of up to two target creatures.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Entwine {3}{W} (Choose both if you pay the entwine cost.)

Infectious Bite

Target creature you control deals damage equal to its power to target creature you don't control. Each opponent gets a poison counter.

Serum Snare

Return target nonland permanent to its owner's hand. If that permanent had mana value 3 or less, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Apex Hawks

Multikicker {1}{W} (You may pay an additional {1}{W} any number of times as you cast this spell.)
Flying
Apex Hawks enters the battlefield with a +1/+1 counter on it for each time it was kicked.

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)