Traumatize

Target player mills half their library, rounded down.

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}.

Archive Trap

If an opponent searched their library this turn, you may pay {0} rather than pay this spell's mana cost.
Target opponent mills thirteen cards.

Murmuring Mystic

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

Bond of Insight

Each player mills four cards. Return up to two instant and/or sorcery cards from your graveyard to your hand. Exile Bond of Insight.

Disturbing Conversion

Flash
Enchant creature
When Disturbing Conversion enters, each player mills two cards.
Enchanted creature gets -X/-0, where X is the number of cards in its controller's graveyard.

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Drownyard Amalgam

When Drownyard Amalgam enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)
{2}{U}: Drownyard Amalgam can't be blocked this turn.

Countermand

Counter target spell. Its controller mills four cards.

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.)

Mocking Sprite

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

Diamond Knight

Vigilance (Attacking doesn't cause this creature to tap.)
As Diamond Knight enters, choose a color.
Whenever you cast a spell of the chosen color, put a +1/+1 counter on Diamond Knight.

Homarid Explorer

When Homarid Explorer enters, target player mills four cards.

Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Dreadwaters

Target player mills X cards, where X is the number of lands you control.

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

Meldweb Curator

When Meldweb Curator enters, put up to one target instant or sorcery card from your graveyard on top of your library.

Sol Ring

Divination

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Island

Chancellor of Tales

Flying
Whenever you cast an Adventure spell, you may copy it. You may choose new targets for the copy.

Treasure Hunt

Reveal cards from the top of your library until you reveal a nonland card, then put all cards revealed this way into your hand.

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.

Train of Thought

Replicate {1}{U} (When you cast this spell, copy it for each time you paid its replicate cost.)
Draw a card.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Flood of Recollection

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