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.

Watcher for Tomorrow

Hideaway 4 (When this creature enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Watcher for Tomorrow enters tapped.
When Watcher for Tomorrow leaves the battlefield, put the exiled card into its owner's hand.

Sol Ring

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Commander's Sphere

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

Momentary Blink

Exile target creature you control, then return it to the battlefield under its owner's control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fiend Hunter

When Fiend Hunter enters, you may exile another target creature.
When Fiend Hunter leaves the battlefield, return the exiled card to the battlefield under its owner's control.

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.)

Thran Dynamo

Mistmeadow Witch

{2}{W}{U}: Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

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.)

Mind Stone

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

Blur

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

Fblthp, the Lost

When Fblthp, the Lost enters, draw a card. If it entered from your library or was cast from your library, draw two cards instead.
When Fblthp becomes the target of a spell, shuffle Fblthp into its owner's library.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Lae'zel's Acrobatics

Exile all nontoken creatures you control, then roll a d20.
1—9 | Return those cards to the battlefield under their owner's control at the beginning of the next end step.
10—20 | Return those cards to the battlefield under their owner's control, then exile them again. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

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.

Scampering Surveyor

When Scampering Surveyor enters, search your library for a basic land card or Cave card, put it onto the battlefield tapped, then shuffle.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Cloudshift

Exile target creature you control, then return that card to the battlefield under your control.

Kor Cartographer

When Kor Cartographer enters, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Justiciar's Portal

Exile target creature you control, then return that card to the battlefield under its owner's control. It gains first strike until end of turn.

Flicker of Fate

Exile target creature or enchantment, then return it to the battlefield under its owner's control.

Circuit Mender

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

Restoration Angel

Flash
Flying
When Restoration Angel enters, you may exile target non-Angel creature you control, then return that card to the battlefield under your control.

Mnemonic Wall

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

Archaeomancer

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

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.

Werefox Bodyguard

Flash
When Werefox Bodyguard enters, exile up to one other target non-Fox creature until Werefox Bodyguard leaves the battlefield.
{1}{W}, Sacrifice Werefox Bodyguard: You gain 2 life.

Cloudblazer

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

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Inspiring Overseer

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

Flickerwisp

Flying
When Flickerwisp enters, exile another target permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Felidar Guardian

When Felidar Guardian enters, you may exile another target permanent you control, then return that card to the battlefield under its owner's control.

Spirited Companion

When Spirited Companion enters, draw a card.

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.

Assimilation Aegis

When Assimilation Aegis enters, exile up to one target creature until Assimilation Aegis leaves the battlefield.
Whenever Assimilation Aegis becomes attached to a creature, for as long as Assimilation Aegis remains attached to it, that creature becomes a copy of a creature card exiled with Assimilation Aegis.
Equip {2}

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.

Candlekeep Sage

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

Panharmonicon

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

Wall of Omens

Defender
When Wall of Omens enters, draw a card.

Aether Channeler

When Aether Channeler enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.