Have

Distinguished Conjurer

Whenever another creature you control enters, you gain 1 life.
{4}{W}, {T}: Exile another target creature you control, then return it to the battlefield under its owner's control.

Brightmare

When Brightmare enters, tap up to one target creature. You gain life equal to that creature's power.

Rambunctious Mutt

When Rambunctious Mutt enters, destroy target artifact or enchantment an opponent controls.

Imperial Aerosaur

Flying
When Imperial Aerosaur enters, another target creature you control gets +1/+1 and gains flying until end of turn.

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.

Valorous Steed

Vigilance (Attacking doesn't cause this creature to tap.)
When Valorous Steed enters, create a 2/2 white Knight creature token with vigilance.

Settle Beyond Reality

Choose one or both —
• Exile target creature you don't control.
• Exile target creature you control, then return it to the battlefield under its owner's control.

Inspiring Overseer

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

Seller of Songbirds

When Seller of Songbirds enters, create a 1/1 white Bird creature token with flying.

Gallant Cavalry

Vigilance (Attacking doesn't cause this creature to tap.)
When Gallant Cavalry enters, create a 2/2 white Knight creature token with vigilance.

Wispweaver Angel

Flying
When Wispweaver Angel enters, you may exile another target creature you control, then return that card to the battlefield under its owner's control.

Panharmonicon

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

Acrobatic Maneuver

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

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.

Thriving Heath

Thriving Heath enters tapped. As it enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

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.

Pierce Strider

When Pierce Strider enters, target opponent loses 3 life.

Cavalry Drillmaster

When Cavalry Drillmaster enters, target creature gets +2/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Blink (Front Card)

Valor in Akros

Whenever a creature you control enters, creatures you control get +1/+1 until end of turn.

Thraben Inspector

When Thraben Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Faith's Fetters

Enchant permanent
When Faith's Fetters enters, you gain 4 life.
Enchanted permanent can't attack or block, and its activated abilities can't be activated unless they're mana abilities.

Plains

Flicker of Fate

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