Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

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.)

Tyranid Prime

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Synapse Creature — Other creatures you control have evolve.

Resourceful Defense

Whenever a permanent you control leaves the battlefield, if it had counters on it, put those counters on target permanent you control.
{4}{W}: Move any number of counters from target permanent you control to another target permanent you control.

Norn's Choirmaster

Flying, first strike
Whenever a commander you control enters or attacks, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Contentious Plan

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

Elesh Norn, Mother of Machines

Vigilance
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Permanents entering don't cause abilities of permanents your opponents control to trigger.

Vorel of the Hull Clade

{G}{U}, {T}: Double the number of each kind of counter on target artifact, creature, or land.

Hamza, Guardian of Arashin

This spell costs {1} less to cast for each creature you control with a +1/+1 counter on it.
Creature spells you cast cost {1} less to cast for each creature you control with a +1/+1 counter on it.

Together Forever

When Together Forever enters, support 2. (Put a +1/+1 counter on each of up to two target creatures.)
{1}: Choose target creature with a counter on it. When that creature dies this turn, return that card to its owner's hand.

Paradoxical Outcome

Return any number of target nonland, nontoken permanents you control to their owners' hands. Draw a card for each card returned to your hand this way.

Agent's Toolkit

Agent's Toolkit enters with a +1/+1 counter, a flying counter, a deathtouch counter, and a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Whenever a creature you control enters, you may move a counter from Agent's Toolkit onto that creature.
{2}, Sacrifice Agent's Toolkit: Draw a card.

Fractal Harness

When Fractal Harness enters, create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it and attach Fractal Harness to it.
Whenever equipped creature attacks, double the number of +1/+1 counters on it.
Equip {2}

Keleth, Sunmane Familiar

Whenever a commander you control attacks, put a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Imoen, Mystic Trickster

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
At the beginning of your end step, if you have the initiative, draw a card. Draw another card if you've completed a dungeon.
Choose a Background (You can have a Background as a second commander.)

Seasoned Dungeoneer

When Seasoned Dungeoneer enters, you take the initiative.
Whenever you attack, target attacking Cleric, Rogue, Warrior, or Wizard gains protection from creatures until end of turn. It explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

Luminous Broodmoth

Flying
Whenever a creature you control without flying dies, return it to the battlefield under its owner's control with a flying counter on it.

Inga and Esika

Creatures you control have vigilance and "{T}: Add one mana of any color. Spend this mana only to cast a creature spell."
Whenever you cast a creature spell, if three or more mana from creatures was spent to cast it, 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.

Boon of Safety

Put a shield counter on target creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Scry 1.

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.)

Legolas Greenleaf

Reach
Legolas Greenleaf can't be blocked by creatures with power 2 or less.
Whenever another legendary creature you control enters, put a +1/+1 counter on Legolas Greenleaf.
Whenever Legolas Greenleaf deals combat damage to a player, draw a card.

White Plume Adventurer

When White Plume Adventurer enters, you take the initiative.
At the beginning of each opponent's upkeep, untap a creature you control. If you've completed a dungeon, untap all creatures you control instead.

Evolution Sage

Landfall — Whenever a land you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Arwen, Mortal Queen

Arwen, Mortal Queen enters with an indestructible counter on it.
{1}, Remove an indestructible counter from Arwen: Another target creature gains indestructible until end of turn. Put a +1/+1 counter and a lifelink counter on that creature and a +1/+1 counter and a lifelink counter on Arwen.

Preston, the Vanisher

Whenever another nontoken creature you control enters, if it wasn't cast, create a token that's a copy of that creature, except it's a 0/1 white Illusion.
{1}{W}, Sacrifice five Illusions: Exile target nonland permanent.

Falco Spara, Pactweaver

Flying, trample
Falco Spara, Pactweaver enters 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.

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.)

Lonis, Cryptozoologist

Whenever another nontoken creature you control enters, investigate.
{T}, Sacrifice X Clues: Target opponent reveals the top X cards of their library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield under your control. That player puts the rest on the bottom of their library in a random order.

Elrond, Lord of Rivendell

Whenever Elrond, Lord of Rivendell or another creature you control enters, scry 1. If this is the second time this ability has resolved this turn, the Ring tempts you.

The Ring Goes South

The Ring tempts you. Then reveal cards from the top of your library until you reveal X land cards, where X is the number of legendary creatures you control. Put those land cards onto the battlefield tapped and the rest on the bottom of your library in a random order.

Lae'zel, Vlaakith's Champion

If you would put one or more counters on a creature or planeswalker you control or on yourself, put that many plus one of each of those kinds of counters on that permanent or player instead.
Choose a Background (You can have a Background as a second commander.)

Winged Temple of Orazca

(Transforms from Hadana's Climb.)
{T}: Add one mana of any color.
{1}{G}{U}, {T}: Target creature you control gains flying and gets +X/+X until end of turn, where X is its power.

Hadana's Climb

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. Then if that creature has three or more +1/+1 counters on it, transform Hadana's Climb.

Hadana's Climb // Winged Temple of Orazca

Elspeth Resplendent

+1: Choose up to one target creature. Put a +1/+1 counter and a counter from among flying, first strike, lifelink, or vigilance on it.
−3: Look at the top seven cards of your library. You may put a permanent card with mana value 3 or less from among them onto the battlefield with a shield counter on it. Put the rest on the bottom of your library in a random order.
−7: Create five 3/3 white Angel creature tokens with flying.

Slippery Bogbonder

Flash
Hexproof
When Slippery Bogbonder enters, put a hexproof counter on target creature. Then move any number of counters from among creatures you control onto that creature.

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

God-Eternal Kefnet

Flying
You may reveal the first card you draw each turn as you draw it. Whenever you reveal an instant or sorcery card this way, copy that card and you may cast the copy. That copy costs {2} less to cast.
When God-Eternal Kefnet dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Ezuri, Stalker of Spheres

When Ezuri, Stalker of Spheres enters, you may pay {3}. If you do, proliferate twice.
Whenever you proliferate, draw a card.

Noble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {G}, {W}, or {U}.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Flowering of the White Tree

Legendary creatures you control get +2/+1 and have ward {1}.
Nonlegendary creatures you control get +1/+1.

Storvald, Frost Giant Jarl

Ward {3}
Other creatures you control have ward {3}.
Whenever Storvald enters or attacks, choose one or both —
• Target creature has base power and toughness 7/7 until end of turn.
• Target creature has base power and toughness 1/1 until end of turn.

Lagrella, the Magpie

When Lagrella, the Magpie enters, exile any number of other target creatures controlled by different players until Lagrella leaves the battlefield. When an exiled card enters under your control this way, put two +1/+1 counters on it.

Simic Ascendancy

{1}{G}{U}: Put a +1/+1 counter on target creature you control.
Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on Simic Ascendancy.
At the beginning of your upkeep, if Simic Ascendancy has twenty or more growth counters on it, you win the game.

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.

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.)

The Ozolith

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.
At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

Forgotten Ancient

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient.
At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Esior, Wardwing Familiar

Flying
Spells your opponents cast that target one or more commanders you control cost {3} more to cast.
Partner (You can have two commanders if both have partner.)

Cankerbloom

{1}, Sacrifice Cankerbloom: Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Crystalline Giant

At the beginning of combat on your turn, choose a kind of counter at random that Crystalline Giant doesn't have on it from among flying, first strike, deathtouch, hexproof, lifelink, menace, reach, trample, vigilance, and +1/+1. Put a counter of that kind on Crystalline Giant.

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Shortcut to Mushrooms

When Shortcut to Mushrooms enters, the Ring tempts you.
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, put a +1/+1 counter on target creature you control.

Novijen, Heart of Progress

{T}: Add {C}.
{G}{U}, {T}: Put a +1/+1 counter on each creature that entered this turn.

Contractual Safeguard

Addendum — If you cast this spell during your main phase, put a shield counter on a creature you control. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Choose a kind of counter on a creature you control. Put a counter of that kind on each other creature you control.

Deepglow Skate

When Deepglow Skate enters, double the number of each kind of counter on any number of target permanents.

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.

Roalesk, Apex Hybrid

Flying, trample
When Roalesk, Apex Hybrid enters, put two +1/+1 counters on another target creature you control.
When Roalesk dies, proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Counterbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, counter that spell if it has the same mana value as the revealed card.

Pippin, Guard of the Citadel

Vigilance, ward {1}
{T}: Another target creature you control gains protection from the card type of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that type.)

Legolas, Counter of Kills

Reach
Whenever you scry, if Legolas, Counter of Kills is tapped, you may untap it. Do this only once each turn.
Whenever a creature an opponent controls dies, put a +1/+1 counter on Legolas.

Hama Pashar, Ruin Seeker

Room abilities of dungeons you own trigger an additional time.

Bloated Contaminator

Trample
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever Bloated Contaminator 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.)