Aven Riftwatcher

Flying
Vanishing 3 (This creature enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When this creature enters or leaves the battlefield, you gain 2 life.

Archaeomancer

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

Crookclaw Transmuter

Flash
Flying
When this creature enters, switch target creature's power and toughness until end of turn.

Dusk Legion Zealot

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

Dismal Backwater

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

Demon's Disciple

When this creature enters, each player sacrifices a creature or planeswalker of their choice.

Augury Owl

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

Dimir Guildgate

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

Carrion Locust

Flying
When this creature enters, exile target card from an opponent's graveyard. If it was a creature card, that player loses 1 life.

Palace Sentinels

When this creature enters, you become the monarch.

Dinrova Horror

When this creature enters, return target permanent to its owner's hand, then that player discards a card.

Citadel Gate

This land enters tapped.
As this land enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Aven Surveyor

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

Chittering Rats

When this creature enters, target opponent puts a card from their hand on top of their library.

Cloudshift

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

Cogwork Wrestler

Flash
When this creature enters, target creature an opponent controls gets -2/-0 until end of turn.

Mulldrifter

Flying
When this creature 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.)

Blind Hunter

Flying
Haunt (When this creature dies, exile it haunting target creature.)
When this creature enters or the creature it haunts dies, target player loses 2 life and you gain 2 life.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Aethersnipe

When this creature enters, return target nonland permanent to its owner's hand.
Evoke {1}{U}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

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.)

Chain Devil

Animate Chains — When this creature enters, each player sacrifices a nontoken creature of their choice.

Azure Fleet Admiral

When this creature enters, you become the monarch.
This creature can't be blocked by creatures the monarch controls.

Burrog Befuddler

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, target creature an opponent controls gets -1/-0 until end of turn.

Burglar Rat

When this creature enters, each opponent discards a card.

Augur of Bolas

When this creature enters, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.