Loran of the Third Path

Vigilance
When Loran enters, destroy up to one target artifact or enchantment.
{T}: You and target opponent each draw a card.

Halo Fountain

{W}, {T}, Untap a tapped creature you control: Create a 1/1 green and white Citizen creature token.
{W}{W}, {T}, Untap two tapped creatures you control: Draw a card.
{W}{W}{W}{W}{W}, {T}, Untap fifteen tapped creatures you control: You win the game.

Mondrak, Glory Dominus

If one or more tokens would be created under your control, twice that many of those tokens are created instead.
{1}{W/P}{W/P}, Sacrifice two other artifacts and/or creatures: Put an indestructible counter on Mondrak. ({W/P} can be paid with either {W} or 2 life.)

Dust Bowl

{T}: Add {C}.
{3}, {T}, Sacrifice a land: Destroy target nonbasic land.

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.

Wall of Omens

Defender
When this creature enters, draw a card.

Aerial Extortionist

Flying
Whenever this creature enters 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.

Sun Titan

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

Allied Teamwork

When this enchantment enters, create a 1/1 white Ally creature token.
Allies you control get +1/+1.

Ichor Wellspring

When this artifact enters or is put into a graveyard from the battlefield, draw a card.

Boreas Charger

Flying
When this creature leaves the battlefield, choose an opponent who controls more lands than you. Search your library for a number of Plains cards equal to the difference, reveal those cards, put one of them onto the battlefield tapped and the rest into your hand, then shuffle.

Plains

Patchwork Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Prophetic Prism

When this artifact enters, draw a card.
{1}, {T}: Add one mana of any color.

Metastatic Evangel

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

Angel of Serenity

Flying
When this creature enters, you may exile up to three other target creatures from the battlefield and/or creature cards from graveyards.
When this creature leaves the battlefield, return the exiled cards to their owners' hands.

Staff of the Storyteller

When this artifact enters, create a 1/1 white Spirit creature token with flying.
Whenever you create one or more creature tokens, put a story counter on this artifact.
{W}, {T}, Remove a story counter from this artifact: Draw a card.

Circuit Mender

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

Knight of the White Orchid

First strike
When this creature enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.

Flickerwisp

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

Mycosynth Wellspring

When this artifact enters or is put into a graveyard from the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Anticausal Vestige

When this creature leaves the battlefield, draw a card, then you may put a permanent card with mana value less than or equal to the number of lands you control from your hand onto the battlefield tapped.
Warp {4} (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.)

Pearl Medallion

White spells you cast cost {1} less to cast.

Appa, Steadfast Guardian

Flash
Flying
When Appa enters, airbend any number of other target nonland permanents you control. (Exile them. While each one is exiled, its owner may cast it for {2} rather than its mana cost.)
Whenever you cast a spell from exile, create a 1/1 white Ally creature token.

Ondu Cleric

Whenever this creature or another Ally you control enters, you may gain life equal to the number of Allies you control.

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.

Another Round

Exile any number of creatures you control, then return them to the battlefield under their owner's control. Then repeat this process X more times.

White Lotus Tile

This artifact enters tapped.
{T}: Add X mana of any one color, where X is the greatest number of creatures you control that have a creature type in common.

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.

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.

Enduring Innocence

Lifelink
Whenever one or more other creatures you control with power 2 or less enter, draw a card. This ability triggers only once each turn.
When Enduring Innocence dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Demolition Field

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

Panharmonicon

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

Tivit, Seller of Secrets

Flying, ward {3}
Council's dilemma — Whenever Tivit enters or deals combat damage to a player, starting with you, each player votes for evidence or bribery. For each evidence vote, investigate. For each bribery vote, create a Treasure token.
While voting, you may vote an additional time. (The votes can be for different choices or for the same choice.)

Aang, Airbending Master

When Aang enters, airbend another target creature. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Whenever one or more creatures you control leave the battlefield without dying, you get an experience counter.
At the beginning of your upkeep, create a 1/1 white Ally creature token for each experience counter you have.

Phelia, Exuberant Shepherd

Flash
Whenever Phelia attacks, exile up to one other target nonland permanent. At the beginning of the next end step, return that card to the battlefield under its owner's control. If it entered under your control, put a +1/+1 counter on Phelia.

Kor Cartographer

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

Swords to Plowshares

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

Abdel Adrian, Gorion's Ward

When Abdel Adrian 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.)

Avatar Enthusiasts

Whenever another Ally you control enters, put a +1/+1 counter on this creature.

Airbender Ascension

When this enchantment enters, airbend up to one target creature.
Whenever a creature you control enters, put a quest counter on this enchantment.
At the beginning of your end step, if this enchantment has four or more quest counters on it, exile up to one target creature you control, then return it to the battlefield under its owner's control.

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.