A Little Chat

Casualty 1 (As you cast this spell, you may sacrifice a creature with power 1 or greater. When you do, copy this spell.)
Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Thassa's Bounty

Draw three cards. Target player mills three cards.

Mind Sculpt

Drowner Initiate

Whenever a player casts a blue spell, you may pay {1}. If you do, target player mills two cards.

Fascination

Choose one —
• Each player draws X cards.
• Each player mills X cards.

Divide by Zero

Return target spell or permanent with mana value 1 or greater to its owner's hand.
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Fact or Fiction

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.

Belltower Sphinx

Flying
Whenever a source deals damage to Belltower Sphinx, that source's controller mills that many cards.

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Thirst for Discovery

Draw three cards. Then discard two cards unless you discard a basic land card.

Sage of Mysteries

Constellation — Whenever an enchantment you control enters, target player mills two cards.

Brainstorm

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

Vapor Snag

Return target creature to its owner's hand. Its controller loses 1 life.

Merrow Witsniper

When Merrow Witsniper enters, target player mills a card.

Thought Scour

Target player mills two cards.
Draw a card.

Sage's Row Denizen

Whenever another blue creature you control enters, target player mills two cards.

Chronic Flooding

Enchant land
Whenever enchanted land becomes tapped, its controller mills three cards.

Ponder

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

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.)

Vedalken Entrancer

Flood of Recollection

Return target instant or sorcery card from your graveyard to your hand. Exile Flood of Recollection.

Kelpie Guide

{T}: Untap another target permanent you control.
{T}: Tap target permanent. Activate only if you control eight or more lands.

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {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.)

Serum Visions

Thought Collapse

Counter target spell. Its controller mills three cards.

Cephalid Broker

{T}: Target player draws two cards, then discards two cards.

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

Peek

Look at target player's hand.
Draw a card.

Library Larcenist

Whenever Library Larcenist attacks, draw a card.

Counter target spell. That spell's controller may draw a card.

Solve the Equation

Search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

Leadership Vacuum

Target player returns each commander they control from the battlefield to the command zone.
Draw a card.

Lethargy Trap

If three or more creatures are attacking, you may pay {U} rather than pay this spell's mana cost.
Attacking creatures get -3/-0 until end of turn.

Deekah, Fractal Theorist

Magecraft — Whenever you cast or copy an instant or sorcery spell, create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is that spell's mana value.
{3}{U}: Target creature token can't be blocked this turn.

Anticipate

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

Merfolk Wayfinder

Flying
When Merfolk Wayfinder enters, reveal the top three cards of your library. Put all Island cards revealed this way into your hand and the rest on the bottom of your library in any order.