Foil

You may discard an Island card and another card rather than pay this spell's mana cost.
Counter target spell.

Geralf's Masterpiece

Flying
Geralf's Masterpiece gets -1/-1 for each card in your hand.
{3}{U}, Discard three cards: Return Geralf's Masterpiece from your graveyard to the battlefield tapped.

Pulse of the Grid

Draw two cards, then discard a card. Then if an opponent has more cards in hand than you, return Pulse of the Grid to its owner's hand.

Ideas Unbound

Draw three cards. Discard three cards at the beginning of the next end step.

Frantic Search

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

Psychic Vortex

Cumulative upkeep—Draw a card. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
At the beginning of your end step, sacrifice a land and discard your hand.

Commandeer

You may exile two blue cards from your hand rather than pay this spell's mana cost.
Gain control of target noncreature spell. You may choose new targets for it. (If that spell is an artifact, enchantment, or planeswalker, the permanent enters under your control.)

Turbulent Dreams

As an additional cost to cast this spell, discard X cards.
Return X target nonland permanents to their owners' hands.

Magus of the Bazaar

{T}: Draw two cards, then discard three cards.

Idle Thoughts

{2}: Draw a card if you have no cards in hand.

Oath of Scholars

At the beginning of each player's upkeep, that player chooses target player who has more cards in hand than they do and is their opponent. The first player may discard their hand and draw three cards.

Slithermuse

When Slithermuse leaves the battlefield, choose an opponent. If that player has more cards in hand than you, draw cards equal to the difference.
Evoke {3}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Disrupting Shoal

You may exile a blue card with mana value X from your hand rather than pay this spell's mana cost.
Counter target spell if its mana value is X.

Alexi, Zephyr Mage

{X}{U}, {T}, Discard two cards: Return X target creatures to their owners' hands.

Attunement

Return Attunement to its owner's hand: Draw three cards, then discard four cards.

Keeper of the Mind

{U}, {T}: Choose target opponent who has at least two more cards in hand than you do as you activate this ability. Draw a card.

Careful Study

Misdirection

You may exile a blue card from your hand rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Balance of Power

If target opponent has more cards in hand than you, draw cards equal to the difference.

Heightened Awareness

As Heightened Awareness enters, discard your hand.
At the beginning of your draw step, draw an additional card.

Breakthrough

Draw four cards, then choose X cards in your hand and discard the rest.

Chamber of Manipulation

Enchant land
Enchanted land has "{T}, Discard a card: Gain control of target creature until end of turn."

Diplomatic Escort

{U}, {T}, Discard a card: Counter target spell or ability that targets a creature.