Oversimplify

Exile all creatures. Each player creates a 0/0 green and blue Fractal creature token and puts a number of +1/+1 counters on it equal to the total power of creatures they controlled that were exiled this way.

Island

Broken Wings

Destroy target artifact, enchantment, or creature with flying.

Dour Port-Mage

Whenever one or more other creatures you control leave the battlefield without dying, draw a card.
{1}{U}, {T}: Return another target creature you control to its owner's hand.

Hinterland Harbor

This land enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Don't Have

Springbloom Druid

When this creature enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Splash Portal

Exile target creature you control, then return it to the battlefield under its owner's control. If that creature is a Bird, Frog, Otter, or Rat, draw a card.

God-Eternal Rhonas

Deathtouch
When God-Eternal Rhonas enters, double the power of each other creature you control until end of turn. Those creatures gain vigilance until end of turn.
When God-Eternal Rhonas dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Blur

Exile target creature you control, then return that card to the battlefield under its owner's control.
Draw a card.

Shared Summons

Search your library for up to two creature cards with different names, reveal them, put them into your hand, then shuffle.

Springheart Nantuko

Bestow {1}{G}
Enchanted creature gets +1/+1.
Landfall — Whenever a land you control enters, you may pay {1}{G} if this permanent is attached to a creature you control. If you do, create a token that's a copy of that creature. If you didn't create a token this way, create a 1/1 green Insect creature token.

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Gala Greeters

Alliance — Whenever another creature you control enters, choose one that hasn't been chosen this turn —
• Put a +1/+1 counter on this creature.
• Create a tapped Treasure token.
• You gain 2 life.

Centaur Chieftain

Haste
Threshold — As long as seven or more cards are in your graveyard, this creature has "When this creature enters, creatures you control get +1/+1 and gain trample until end of turn."

Reclamation Sage

When this creature enters, you may destroy target artifact or enchantment.

Hydroelectric Laboratory

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Hydroelectric Specimen

Flash
When this creature enters, you may change the target of target instant or sorcery spell with a single target to this creature.

Hydroelectric Specimen // Hydroelectric Laboratory

Golden Argosy

Whenever Golden Argosy attacks, exile each creature that crewed it this turn. Return them to the battlefield tapped under their owner's control at the beginning of the next end step.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Extraordinary Journey

When this enchantment enters, exile up to X target creatures. For each of those cards, its owner may play it for as long as it remains exiled.
Whenever one or more nontoken creatures enter, if one or more of them entered from exile or was cast from exile, you draw a card. This ability triggers only once each turn.

Tangled Islet

({T}: Add {G} or {U}.)
This land enters tapped.

Panharmonicon

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

Collective Resistance

Escalate {G} (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Destroy target artifact.
• Destroy target enchantment.
• Target creature gains hexproof and indestructible until end of turn.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Simic Guildgate

This land enters tapped.
{T}: Add {G} or {U}.

Vineglimmer Snarl

As this land enters, you may reveal a Forest or Island card from your hand. If you don't, this land enters tapped.
{T}: Add {G} or {U}.

Y'shtola Rhul

At the beginning of your end step, exile target creature you control, then return it to the battlefield under its owner's control. Then if it's the first end step of the turn, there is an additional end step after this step.

Brainsurge

Draw four cards, then put two cards from your hand on top of your library in any order.

Topiary Stomper

Vigilance (Attacking doesn't cause this creature to tap.)
When this creature enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
This creature can't attack or block unless you control seven or more lands.

Kederekt Leviathan

When this creature enters, return all other nonland permanents to their owners' hands.
Unearth {6}{U} ({6}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Titan of Industry

Reach, trample
When this creature enters, choose two —
• Destroy target artifact or enchantment.
• Target player gains 5 life.
• Create a 4/4 green Rhino Warrior creature token.
• Put a shield counter on a creature you control.

Farhaven Elf

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

Green Slime

Flash
When this creature 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.)

Quandrix Campus

This land enters tapped.
{T}: Add {G} or {U}.
{4}, {T}: Scry 1.

Sol Ring

Kodama of the East Tree

Reach
Whenever another permanent you control enters, if it wasn't put onto the battlefield with this ability, you may put a permanent card with equal or lesser mana value from your hand onto the battlefield.
Partner (You can have two commanders if both have partner.)

Dreamroot Cascade

This land enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Shadow Puppeteers

Flying, ward {2}
When this creature enters, create two 1/1 black Faerie Rogue creature tokens with flying.
Whenever a creature you control with flying attacks, you may have it become a red Dragon with base power and toughness 4/4 in addition to its other colors and types until end of turn.

Arcane Signet

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

Aid from the Cowl

Revolt — At the beginning of your end step, if a permanent left the battlefield under your control this turn, reveal the top card of your library. If it's a permanent card, you may put it onto the battlefield. Otherwise, you may put it on the bottom of your library.

Ghostly Flicker

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

Siren's Ruse

Exile target creature you control, then return that card to the battlefield under its owner's control. If a Pirate was exiled this way, draw a card.

Teferi's Time Twist

Exile target permanent you control. Return that card to the battlefield under its owner's control at the beginning of the next end step. If it enters as a creature, it enters with an additional +1/+1 counter on it.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Quickling

Flash (You may cast this spell any time you could cast an instant.)
Flying
When this creature enters, sacrifice it unless you return another creature you control to its owner's hand.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Naturalize

Circuit Mender

When this creature enters, you gain 2 life.
When this creature leaves the battlefield, draw a card.

Winding Canyons

{T}: Add {C}.
{2}, {T}: You may cast creature spells this turn as though they had flash.

Voyager Staff

{2}, Sacrifice this artifact: Exile target creature. Return the exiled card to the battlefield under its owner's control at the beginning of the next end step.

Cemetery Prowler

Vigilance
Whenever this creature enters or attacks, exile a card from a graveyard.
Spells you cast cost {1} less to cast for each card type they share with cards exiled with this creature.

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Simic Signet

Planar Incision

Exile target artifact or creature, then return it to the battlefield under its owner's control with a +1/+1 counter on it.

Wildsong Howler

Whenever this creature enters or transforms into Wildsong Howler, look at the top six cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Howlpack Piper

This spell can't be countered.
{1}{G}, {T}: You may put a creature card from your hand onto the battlefield. If it's a Wolf or Werewolf, untap this creature. Activate only as a sorcery.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Howlpack Piper // Wildsong Howler

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.)

Soul of the Harvest

Trample
Whenever another nontoken creature you control enters, you may draw a card.

Whirler Rogue

When this creature enters, create two 1/1 colorless Thopter artifact creature tokens with flying.
Tap two untapped artifacts you control: Target creature can't be blocked this turn.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When this creature enters, destroy target artifact, enchantment, or land.

Vivien, Champion of the Wilds

You may cast creature spells as though they had flash.
+1: Until your next turn, up to one target creature gains vigilance and reach.
−2: Look at the top three cards of your library. Exile one face down and put the rest on the bottom of your library in any order. For as long as it remains exiled, you may cast it if it's a creature spell.

Season of Weaving

Choose up to five {P} worth of modes. You may choose the same mode more than once.
{P} — Draw a card.
{P}{P} — Choose an artifact or creature you control. Create a token that's a copy of it.
{P}{P}{P} — Return each nonland, nontoken permanent to its owner's hand.

Displacement Wave

Return all nonland permanents with mana value X or less to their owners' hands.

Flood of Tears

Return all nonland permanents to their owners' hands. If you return four or more nontoken permanents you control this way, you may put a permanent card from your hand onto the battlefield.

Elvish Visionary

Earthshaker Giant

Trample
When this creature enters, other creatures you control get +3/+3 and gain trample until end of turn.

Tribute to the World Tree

Whenever a creature you control enters, draw a card if its power is 3 or greater. Otherwise, put two +1/+1 counters on it.

Sakashima of a Thousand Faces

You may have Sakashima enter as a copy of another creature you control, except it has Sakashima's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Forest

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice this land: You may cast spells this turn as though they had flash.

Kappa Tech-Wrecker

Ninjutsu {1}{G}
This creature enters with a deathtouch counter on it.
Whenever this creature deals combat damage to a player, you may remove a deathtouch counter from it. When you do, exile target artifact or enchantment that player controls.

Temple of Mystery

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {G} or {U}.

Rejuvenating Springs

This land enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Endless Sands

{T}: Add {C}.
{2}, {T}: Exile target creature you control.
{4}, {T}, Sacrifice this land: Return each creature card exiled with this land to the battlefield under its owner's control.

Summon: Fenrir

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Crescent Fang — Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
II — Heavenward Howl — When you next cast a creature spell this turn, that creature enters with an additional +1/+1 counter on it.
III — Ecliptic Growl — Draw a card if you control the creature with the greatest power or tied for the greatest power.

Sword of Hearth and Home

Equipped creature gets +2/+2 and has protection from green and from white.
Whenever equipped creature deals combat damage to a player, exile up to one target creature you own, then search your library for a basic land card. Put both cards onto the battlefield under your control, then shuffle.
Equip {2}

Uro, Titan of Nature's Wrath

When Uro enters, sacrifice it unless it escaped.
Whenever Uro enters or attacks, you gain 3 life and draw a card, then you may put a land card from your hand onto the battlefield.
Escape—{G}{G}{U}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Devastation Tide

Return all nonland permanents to their owners' hands.
Miracle {1}{U} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Aether Vial

At the beginning of your upkeep, you may put a charge counter on this artifact.
{T}: You may put a creature card with mana value equal to the number of charge counters on this artifact from your hand onto the battlefield.

Coiling Oracle

When this creature enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Farseek

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

Identity Thief

Whenever this creature attacks, you may exile another target nontoken creature. If you do, this creature becomes a copy of that creature until end of turn. Return the exiled card to the battlefield under its owner's control at the beginning of the next end step.

Thornwood Falls

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

Botanical Sanctum

This land enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {U}.

Alchemist's Refuge

{T}: Add {C}.
{G}{U}, {T}: You may cast spells this turn as though they had flash.

Hornet Queen

Flying, deathtouch
When this creature enters, create four 1/1 green Insect creature tokens with flying and deathtouch.

Mizzium Meddler

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, you may change a target of target spell or ability to this creature.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Sutina, Speaker of the Tajuru

When Sutina enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Whenever Sutina attacks, you may return a land you control to its owner's hand. When you do, put a +1/+1 counter on target creature.

Incongruity

Exile target creature. That creature's controller creates a 3/3 green Frog Lizard creature token.

Incubation

Look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Incubation // Incongruity

Halana, Kessig Ranger

Reach
Whenever another creature you control enters, you may pay {2}. When you do, that creature deals damage equal to its power to target creature.
Partner (You can have two commanders if both have partner.)

Cemetery Illuminator

Flying
Whenever this creature enters or attacks, exile a card from a graveyard.
You may look at the top card of your library any time.
Once each turn, you may cast a spell from the top of your library if it shares a card type with a card exiled with this creature.

Command Tower

Craterhoof Behemoth

Haste
When this creature enters, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.

Gossip's Talent

(Gain the next level as a sorcery to add its ability.)
Whenever a creature you control enters, surveil 1.
{1}{U}: Level 2
Whenever you attack, target attacking creature with power 3 or less can't be blocked this turn.
{3}{U}: Level 3
Whenever a creature you control deals combat damage to a player, you may exile it, then return it to the battlefield under its owner's control.

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Starfield Vocalist

If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Warp {1}{U} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Ice-Fang Coatl

Flash
Flying
When this creature enters, draw a card.
This creature has deathtouch as long as you control at least three other snow permanents.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Experimental Aviator

Flying
When this creature enters, create two 1/1 colorless Thopter artifact creature tokens with flying.

Wall of Blossoms

Defender
When this creature enters, draw a card.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.