Spell Pierce

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

Tome Scour

Ponder

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

Venture Deeper

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

Merfolk Secretkeeper

Merfolk Secretkeeper // Venture Deeper

Thought Scour

Target player mills two cards.
Draw a card.

Jace's Erasure

Whenever you draw a card, you may have target player mill a card.

Brainstorm

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

Counterspell

Compelling Argument

Target player mills five cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

Nihil Spellbomb

{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Dream Twist

Target player mills three cards.
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Memory Sluice

Target player mills four cards.
Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Jace's Phantasm

Flying
Jace's Phantasm gets +4/+4 as long as an opponent has ten or more cards in their graveyard.

Island

Lonely Sandbar

Lonely Sandbar enters tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Vision Charm

Choose one —
• Target player mills four cards.
• Choose a land type and a basic land type. Each land of the first chosen type becomes the second chosen type until end of turn.
• Target artifact phases out. (While it's phased out, it's treated as though it doesn't exist. It phases in before its controller untaps during their next untap step.)

Stream of Thought

Target player mills four cards. You shuffle up to four cards from your graveyard into your library.
Replicate {2}{U}{U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)