Confounding Riddle

Choose one —
• Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard.
• Counter target spell unless its controller pays {4}.

Mystic Confluence

Choose three. You may choose the same mode more than once.
• Counter target spell unless its controller pays {3}.
• Return target creature to its owner's hand.
• Draw a card.

Behold the Multiverse

Scry 2, then draw two cards.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Consider

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

Melek, Reforged Researcher

Melek, Reforged Researcher's power and toughness are each equal to twice the number of instant and sorcery cards in your graveyard.
The first instant or sorcery spell you cast each turn costs {3} less to cast.

Sublime Epiphany

Choose one or more —
• Counter target spell.
• Counter target activated or triggered ability.
• Return target nonland permanent to its owner's hand.
• Create a token that's a copy of target creature you control.
• Target player draws a card.

Soul Read

Choose one —
• Counter target spell unless its controller pays {4}.
• Draw two cards.

Spellgyre

Choose one —
• Counter target spell.
• Surveil 2, then draw two cards. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Chemister's Insight

Draw two cards.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Curate

Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Draw a card.

Quick Study

Sudden Insight

Draw a card for each different mana value among nonland cards in your graveyard.

Rain of Revelation

Ertai's Meddling

X can't be 0.
Target spell's controller exiles it with X delay counters on it.
At the beginning of each of that player's upkeeps, if that card is exiled, remove a delay counter from it. If the card has no delay counters on it, the player puts it onto the stack as a copy of the original spell.

Rewind

Counter target spell. Untap up to four lands.

Spell Swindle

Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Supreme Will

Choose one —
• Counter target spell unless its controller pays {3}.
• 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.

Unwind

Counter target noncreature spell. Untap up to three lands.

Hurl into History

Counter target artifact or creature spell. Discover X, where X is that spell's mana value. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Shadow Rift

Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)
Draw a card.

Exclude

Counter target creature spell.
Draw a card.

Rowdy Research

This spell costs {1} less to cast for each creature that attacked this turn.
Draw three cards.

Keep Watch

Gale's Redirection

Exile target spell, then roll a d20 and add that spell's mana value.
1—14 | You may cast the exiled card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.
15+ | You may cast the exiled card without paying its mana cost for as long as it remains exiled.

Desertion

Counter target spell. If an artifact or creature spell is countered this way, put that card onto the battlefield under your control instead of into its owner's graveyard.

Overwhelming Intellect

Counter target creature spell. Draw cards equal to that spell's mana value.

Might of the Meek

Target creature gains trample until end of turn. It also gets +1/+0 until end of turn if you control a Mouse.
Draw a card.

Delightful Discovery

This spell costs {1} less to cast for each spell your opponents have cast this turn.
Scry 2, then draw two cards. (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.)

Into the Story

This spell costs {3} less to cast if an opponent has seven or more cards in their graveyard.
Draw four cards.

Summary Dismissal

Exile all other spells and counter all abilities.

Access Denied

Counter target spell. Create X 1/1 colorless Thopter artifact creature tokens with flying, where X is that spell's mana value.

Practical Research

Draw four cards. Then discard two cards unless you discard an instant or sorcery card.

Reinterpret

Counter target spell. You may cast a spell with equal or lesser mana value from your hand without paying its mana cost.

Scatter Arc

Counter target noncreature spell.
Draw a card.

Dismiss

Reverse the Polarity

Choose one —
• Counter all other spells.
• Switch each creature's power and toughness until end of turn.
• Creatures can't be blocked this turn.

Hornswoggle

Counter target creature spell. You create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")