Vantress Paladin

Flying
Adamant — If at least three blue mana was spent to cast this spell, Vantress Paladin enters with a +1/+1 counter on it.

Scent of Brine

Reveal any number of blue cards in your hand. Counter target spell unless its controller pays {1} for each card revealed this way.

Mocking Sprite

Flying
Instant and sorcery spells you cast cost {1} less to cast.

Stormbound Geist

Flying
Stormbound Geist can block only creatures with flying.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Island

Frightful Delusion

Counter target spell unless its controller pays {1}. That player discards a card.

Mirran Spy

Flying
Whenever you cast an artifact spell, you may untap target creature.

Essence Scatter

Negate

Stitched Drake

As an additional cost to cast this spell, exile a creature card from your graveyard.
Flying

Shriekgeist

Flying
Whenever Shriekgeist deals combat damage to a player, that player mills two cards.

Academy Drake

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Flying
If Academy Drake was kicked, it enters with two +1/+1 counters on it.

Dive Down

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Tattered Haunter

Flying
Tattered Haunter can block only creatures with flying.

Thornwind Faeries

Flying
{T}: Thornwind Faeries deals 1 damage to any target.

Convolute

Counter target spell unless its controller pays {4}.

Slow Motion

Enchant creature
At the beginning of the upkeep of enchanted creature's controller, that player sacrifices that creature unless they pay {2}.
When Slow Motion is put into a graveyard from the battlefield, return Slow Motion to its owner's hand.

Turn Aside

Counter target spell that targets a permanent you control.

Hinterland Drake

Flying
Hinterland Drake can't block artifact creatures.

Run Away Together

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

Waterknot

Enchant creature
When Waterknot enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Cancel

Flip the Switch

Counter target spell unless its controller pays {4}. Create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

Veiled Serpent

When an opponent casts a spell, if Veiled Serpent is an enchantment, Veiled Serpent becomes a 4/4 Serpent creature with "This creature can't attack unless defending player controls an Island."
Cycling {2} ({2}, Discard this card: Draw a card.)

Fatigue

Target player skips their next draw step.

Wormfang Drake

Flying
When Wormfang Drake enters, sacrifice it unless you exile a creature you control other than Wormfang Drake.
When Wormfang Drake leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Dream Twist

Target player mills three cards.
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)