Echo Tracer

Morph {2}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Echo Tracer is turned face up, return target creature to its owner's hand.

Aquamorph Entity

As Aquamorph Entity enters the battlefield or is turned face up, it becomes your choice of 5/1 or 1/5.
Morph {2}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Faerie Impostor

Flying
When Faerie Impostor enters the battlefield, sacrifice it unless you return another creature you control to its owner's hand.

Master Decoy

Mana Leak

Counter target spell unless its controller pays {3}.

Coral Trickster

Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Coral Trickster is turned face up, you may tap or untap target permanent.

Traumatic Visions

Counter target spell.
Basic landcycling {1}{U} ({1}{U}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Stonecloaker

Flash
Flying
When Stonecloaker enters the battlefield, return a creature you control to its owner's hand.
When Stonecloaker enters the battlefield, exile target card from a graveyard.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Lightning Angel

Hussar Patrol

Flash (You may cast this spell any time you could cast an instant.)
Vigilance

Island

Stave Off

Target creature gains protection from the color of your choice until end of turn.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Steam Augury

Reveal the top five cards of your library and separate them into two piles. An opponent chooses one of those piles. Put that pile into your hand and the other into your graveyard.

Jeskai Elder

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Jeskai Elder deals combat damage to a player, you may draw a card. If you do, discard a card.

Sparkmage Apprentice

When Sparkmage Apprentice enters the battlefield, it deals 1 damage to any target.

Repeal

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

Inferno Trap

If you've been dealt damage by two or more creatures this turn, you may pay {R} rather than pay this spell's mana cost.
Inferno Trap deals 4 damage to target creature.

Plains

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Kor Hookmaster

When Kor Hookmaster enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Fleeting Distraction

Target creature gets -1/-0 until end of turn.
Draw a card.

Thousand Winds

Flying
Morph {5}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Thousand Winds is turned face up, return all other tapped creatures to their owners' hands.

Willbender

Morph {1}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Willbender is turned face up, change the target of target spell or ability with a single target.

Sphinx of Uthuun

Flying
When Sphinx of Uthuun enters the battlefield, reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Mountain

Lone Missionary

When Lone Missionary enters the battlefield, you gain 4 life.

Hold the Line

Blocking creatures get +7/+7 until end of turn.

Mystic Monastery

Mystic Monastery enters the battlefield tapped.
{T}: Add {U}, {R}, or {W}.

Faerie Invaders

Flash (You may cast this spell any time you could cast an instant.)
Flying

Whiplash Trap

If an opponent had two or more creatures enter the battlefield under their control this turn, you may pay {U} rather than pay this spell's mana cost.
Return two target creatures to their owners' hands.

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis the Omnipotent to its owner's hand.

Fathom Seer

Morph—Return two Islands you control to their owner's hand. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Fathom Seer is turned face up, draw two cards.

Arrow Volley Trap

If four or more creatures are attacking, you may pay {1}{W} rather than pay this spell's mana cost.
Arrow Volley Trap deals 5 damage divided as you choose among any number of target attacking creatures.

Swift Justice

Until end of turn, target creature gets +1/+0 and gains first strike and lifelink.