Serpentine Ambush

Until end of turn, target creature becomes a blue Serpent with base power and toughness 5/5.

Skywarp Skaab

Flying
When this creature enters, you may exile two creature cards from your graveyard. If you do, draw a card.

Soulcipher Board

This artifact enters with three omen counters on it.
{1}{U}, {T}: Look at the top two cards of your library. Put one of them into your graveyard.
Whenever a creature card is put into your graveyard from anywhere, remove an omen counter from this artifact. Then if it has no omen counters on it, transform it.

Rather than consort with demons, the Quietus Cult seeks wisdom from the dead.

Cipherbound Spirit

Flying
This creature can block only creatures with flying.
{3}{U}: Draw two cards, then discard a card.

Soulcipher Board // Cipherbound Spirit

Steelclad Spirit

Defender
Whenever an enchantment you control enters, this creature can attack this turn as though it didn't have defender.

A-Stitched Assistant

Stitched Assistant

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, scry 1, then draw a card. (To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Stormchaser Drake

Flying
Whenever this creature becomes the target of a spell you control, draw a card.

Soul-Guide Gryff

Flying
When this creature enters, exile up to one target card from a graveyard.

Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Blood

Syphon Essence

Counter target creature or planeswalker spell. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Thirst for Discovery

Draw three cards. Then discard two cards unless you discard a basic land card.

Wanderlight Spirit

Flying
This creature can block only creatures with flying.

Wash Away

Cleave {1}{U}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Counter target spell [that wasn't cast from its owner's hand].

Whispering Wizard

Spirit

Whenever you cast a noncreature spell, create a 1/1 white Spirit creature token with flying. This ability triggers only once each turn.

Winged Portent

Cleave {4}{G}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Draw a card for each creature you control [with flying].

Witness the Future

Target player shuffles up to four target cards from their graveyard into their library. You look at the top four cards of your library, then put one of those cards into your hand and the rest on the bottom of your library in a random order.

Wretched Throng

When this creature dies, you may search your library for a card named Wretched Throng, reveal it, put it into your hand, then shuffle.

Innistrad: Double Feature