Inquisitor Exarch

When Inquisitor Exarch enters, choose one —
• You gain 2 life.
• Target opponent loses 2 life.

Azorius Justiciar

When Azorius Justiciar enters, detain up to two target creatures your opponents control. (Until your next turn, those creatures can't attack or block and their activated abilities can't be activated.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

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.

Eye of Singularity

When Eye of Singularity enters, destroy each permanent with the same name as another permanent, except for basic lands. They can't be regenerated.
Whenever a permanent other than a basic land enters, destroy all other permanents with that name. They can't be regenerated.

Kemba's Skyguard

Flying
When Kemba's Skyguard enters, you gain 2 life.

Counterspell

Island

Monk Realist

When Monk Realist enters, destroy target enchantment.

Unsummon

Return target creature to its owner's hand.

Banisher Priest

When Banisher Priest enters, exile target creature an opponent controls until Banisher Priest leaves the battlefield.

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.

Aether Adept

When Aether Adept enters, return target creature to its owner's hand.

Plains

Faerie Artisans

Flying
Whenever a nontoken creature an opponent controls enters, create a token that's a copy of that creature except it's an artifact in addition to its other types. Then exile all other tokens created with Faerie Artisans.