Breath of the Sleepless

You may cast Spirit spells as though they had flash.
Whenever you cast a creature spell during an opponent's turn, tap up to one target creature.

Kor Skyfisher

Flying
When Kor Skyfisher enters, return a permanent you control to its owner's hand.

Paradoxical Outcome

Return any number of target nonland, nontoken permanents you control to their owners' hands. Draw a card for each card returned to your hand this way.

Reflector Mage

When Reflector Mage enters, return target creature an opponent controls to its owner's hand. That creature's owner can't cast spells with the same name as that creature until your next turn.

Ballynock Trapper

{T}: Tap target creature.
Whenever you cast a white spell, you may untap Ballynock Trapper.

Umbilicus

At the beginning of each player's upkeep, that player may pay 2 life. If they don't, they return a permanent they control to its owner's hand.

Artificer's Assistant

Flying
Whenever you cast a historic spell, scry 1. (Artifacts, legendaries, and Sagas are historic. To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Sunken Hope

At the beginning of each player's upkeep, that player returns a creature they control to its owner's hand.

Saiba Cryptomancer

Flash
Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Hexproof

Shield Sphere

Defender
Whenever Shield Sphere blocks, put a -0/-1 counter on it.

Nurturing Pixie

Flying
When Nurturing Pixie enters, return up to one target non-Faerie, nonland permanent you control to its owner's hand. If a permanent was returned this way, put a +1/+1 counter on Nurturing Pixie.

Defiler of Faith

Vigilance
As an additional cost to cast white permanent spells, you may pay 2 life. Those spells cost {W} less to cast if you paid life this way. This effect reduces only the amount of white mana you pay.
Whenever you cast a white permanent spell, create a 1/1 white Soldier creature token.

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.)

Honorable Scout

When Honorable Scout enters, you gain 2 life for each black and/or red creature target opponent controls.

Harrier Strix

Flying
When Harrier Strix enters, tap target permanent.
{2}{U}: Draw a card, then discard a card.

Customs Depot

Whenever you cast a creature spell, you may pay {1}. If you do, draw a card, then discard a card.

Saltskitter

Whenever another creature enters, exile Saltskitter. Return Saltskitter to the battlefield under its owner's control at the beginning of the next end step.

Cathedral Sanctifier

When Cathedral Sanctifier enters, you gain 3 life.

Contemplation

Whenever you cast a spell, you gain 1 life.

Network Disruptor

Flying
When Network Disruptor enters, tap target permanent.

Defiler of Dreams

Flying
As an additional cost to cast blue permanent spells, you may pay 2 life. Those spells cost {U} less to cast if you paid life this way. This effect reduces only the amount of blue mana you pay.
Whenever you cast a blue permanent spell, draw a card.

Memnite

Phyrexian Walker

Niambi, Esteemed Speaker

Flash
When Niambi, Esteemed Speaker enters, you may return another target creature you control to its owner's hand. If you do, you gain life equal to that creature's mana value.
{1}{W}{U}, {T}, Discard a legendary card: Draw two cards.

Whitemane Lion

Flash
When Whitemane Lion enters, return a creature you control to its owner's hand.

Cemetery Protector

Flash
When Cemetery Protector enters, exile a card from a graveyard.
Whenever you play a land or cast a spell, if it shares a card type with the exiled card, create a 1/1 white Human creature token.

Genku, Future Shaper

Whenever another nontoken permanent you control leaves the battlefield, choose one that hasn't been chosen this turn. Create a creature token with those characteristics.
• 2/2 white Fox with vigilance.
• 1/2 blue Moonfolk with flying.
• 1/1 black Rat with lifelink.
{3}{W}{U}: Put a +1/+1 counter on each creature you control.

Faerie Seer

Flying
When Faerie Seer enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Shrieking Drake

Flying
When Shrieking Drake enters, return a creature you control to its owner's hand.

Blood Clock

At the beginning of each player's upkeep, that player returns a permanent they control to its owner's hand unless they pay 2 life.

Kefnet's Monument

Blue creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.