Counterspell

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Unruly Catapult

Defender
{T}: Unruly Catapult deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Unruly Catapult.

Blistercoil Weird

Whenever you cast an instant or sorcery spell, Blistercoil Weird gets +1/+1 until end of turn. Untap it.

Kiln Fiend

Whenever you cast an instant or sorcery spell, Kiln Fiend gets +3/+0 until end of turn.

Nivix Cyclops

Defender
Whenever you cast an instant or sorcery spell, Nivix Cyclops gets +3/+0 until end of turn and can attack this turn as though it didn't have defender.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Erebor Flamesmith

Whenever you cast an instant or sorcery spell, Erebor Flamesmith deals 1 damage to each opponent.

Unwind

Counter target noncreature spell. Untap up to three lands.

Goblin Electromancer

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

Seething Song

Festival Crasher

Whenever you cast an instant or sorcery spell, Festival Crasher gets +2/+0 until end of turn.

Fire Whip

Enchant creature you control
Enchanted creature has "{T}: This creature deals 1 damage to any target."
Sacrifice Fire Whip: Fire Whip deals 1 damage to any target.

Swiftwater Cliffs

Swiftwater Cliffs enters tapped.
When Swiftwater Cliffs enters, you gain 1 life.
{T}: Add {U} or {R}.

Halimar Depths

Halimar Depths enters tapped.
When Halimar Depths enters, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Power of Fire

Enchant creature
Enchanted creature has "{T}: This creature deals 1 damage to any target."

Ophidian Eye

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

You See a Guard Approach

Choose one —
• Distract the Guard — Tap target creature.
• Hide — Target creature you control gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Expedite

Target creature gains haste until end of turn.
Draw a card.

Lavamancer's Skill

Enchant creature
Enchanted creature has "{T}: This creature deals 1 damage to target creature."
As long as enchanted creature is a Wizard, it has "{T}: This creature deals 2 damage to target creature."

Windrider Wizard

Flying
Whenever you cast an instant, sorcery, or Wizard spell, you may draw a card. If you do, discard a card.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Firebrand Archer

Whenever you cast a noncreature spell, Firebrand Archer deals 1 damage to each opponent.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Mocking Sprite

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

Guttersnipe

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

Merchant Scroll

Search your library for a blue instant card, reveal that card, put it into your hand, then shuffle.

Crash Through

Creatures you control gain trample until end of turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Ghitu Amplifier

Kicker {2}{U} (You may pay an additional {2}{U} as you cast this spell.)
When Ghitu Amplifier enters, if it was kicked, return target creature an opponent controls to its owner's hand.
Whenever you cast an instant or sorcery spell, Ghitu Amplifier gets +2/+0 until end of turn.

Psionic Gift

Mana Geyser

Add {R} for each tapped land your opponents control.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.)

Mizzium Skin

Target creature you control gets +0/+1 and gains hexproof until end of turn.
Overload {1}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Shell Shield

Kicker {1} (You may pay an additional {1} as you cast this spell.)
Target creature you control gets +0/+3 until end of turn. If this spell was kicked, that creature also gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Aven Wind Mage

Flying
Whenever you cast an instant or sorcery spell, Aven Wind Mage gets +1/+1 until end of turn.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Wee Dragonauts

Flying
Whenever you cast an instant or sorcery spell, Wee Dragonauts gets +2/+0 until end of turn.

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Sigil of Sleep

Enchant creature
Whenever enchanted creature deals damage to a player, return target creature that player controls to its owner's hand.

Ponder

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

Hermetic Study

Negate

Snap

Return target creature to its owner's hand. Untap up to two lands.

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Preordain

Scry 2, then draw a card. (To 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.)

Quicksilver Dagger

Enchant creature
Enchanted creature has "{T}: This creature deals 1 damage to target player or planeswalker. You draw a card."

Arcane Teachings

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets +2/+2 and has "{T}: This creature deals 1 damage to any target."