Boomerang

Return target permanent to its owner's hand.

Merfolk Trickster

Flash
When this creature enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Skywatcher Adept

Level up {3} ({3}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 1-2
2/2
Flying
LEVEL 3+
4/2
Flying

Spiketail Hatchling

Flying (This creature can't be blocked except by creatures with flying or reach.)
Sacrifice this creature: Counter target spell unless its controller pays {1}.

Unsummon

Return target creature to its owner's hand.

Master of Waves

Protection from red
Elemental creatures you control get +1/+1.
When this creature enters, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

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.)

Repeal

Return target nonland permanent with mana value X to its owner's hand.
Draw a card.

Spell Pierce

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

Jace's Phantasm

Flying
This creature gets +4/+4 as long as an opponent has ten or more cards in their graveyard.

Cerulean Drake

Flying
Protection from red (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything red.)
Sacrifice this creature: Counter target spell that targets you.

Ninja of the Deep Hours

Ninjutsu {1}{U} ({1}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, you may draw a card.

Faerie Impostor

Flying
When this creature enters, sacrifice it unless you return another creature you control to its owner's hand.

Mausoleum Wanderer

Flying
Whenever another Spirit you control enters, this creature gets +1/+1 until end of turn.
Sacrifice this creature: Counter target instant or sorcery spell unless its controller pays {X}, where X is this creature's power.

Lazotep Plating

Amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
You and permanents you control gain hexproof until end of turn. (You and they can't be the targets of spells or abilities your opponents control.)

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice this Aura.

Arrester's Admonition

Return target creature to its owner's hand.
Addendum — If you cast this spell during your main phase, draw a card.

Cloudfin Raptor

Flying
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Spellstutter Sprite

Flash
Flying
When this creature enters, counter target spell with mana value X or less, where X is the number of Faeries you control.

Force Spike

Counter target spell unless its controller pays {1}.

Smuggler's Copter

Flying
Whenever this Vehicle attacks or blocks, you may draw a card. If you do, discard a card.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Essence Capture

Counter target creature spell. Put a +1/+1 counter on up to one target creature you control.

Cloud Sprite

Flying (This creature can't be blocked except by creatures with flying or reach.)
This creature can block only creatures with flying.

Favorable Winds

Creatures you control with flying get +1/+1.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Zephyr Sprite

Kasmina, Enigmatic Mentor

Spells your opponents cast that target a creature or planeswalker you control cost {2} more to cast.
−2: Create a 2/2 blue Wizard creature token. Draw a card, then discard a card.

Moonblade Shinobi

Ninjutsu {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, create a 1/1 blue Illusion creature token with flying.

Faerie Seer

Flying
When this creature 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.)

Cloudseeder

Flying
{U}, {T}, Discard a card: Create a 1/1 blue Faerie creature token named Cloud Sprite. It has flying and "This token can block only creatures with flying."

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Negate

Gigadrowse

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Tap target permanent.

Pteramander

Flying
{7}{U}: Adapt 4. This ability costs {1} less to activate for each instant and sorcery card in your graveyard. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)

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.

Quickling

Flash (You may cast this spell any time you could cast an instant.)
Flying
When this creature enters, sacrifice it unless you return another creature you control to its owner's hand.

Dimensional Infiltrator

Devoid (This card has no color.)
Flash
Flying
{1}{C}: Target opponent exiles the top card of their library. If it's a land card, you may return this creature to its owner's hand. ({C} represents colorless mana.)

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.

Essence Scatter

Quench

Counter target spell unless its controller pays {2}.

Island

Blink of an Eye

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)