Kefnet's Monument

Blue creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Psychic Corrosion

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

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Aetherspouts

For each attacking creature, its owner puts it on their choice of the top or bottom of their library.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Ponder

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

Counterspell

Sky Diamond

Increasing Confusion

Target player mills X cards. If this spell was cast from a graveyard, that player mills twice that many cards instead.
Flashback {X}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sphinx's Tutelage

Whenever you draw a card, target opponent mills two cards. If two nonland cards that share a color were milled this way, repeat this process.
{5}{U}: Draw a card, then discard a card.

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

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.

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.

Claustrophobia

Enchant creature
When Claustrophobia enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Dramatic Reversal

Untap all nonland permanents you control.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Memory Erosion

Whenever an opponent casts a spell, that player mills two cards.

Countermand

Counter target spell. Its controller mills four cards.

Mass Appeal

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Jace, Memory Adept

+1: Draw a card. Target player mills a card.
0: Target player mills ten cards.
−7: Any number of target players each draw twenty cards.

Drowned Secrets

Whenever you cast a blue spell, target player mills two cards.

Island

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Visions of Beyond

Draw a card. If a graveyard has twenty or more cards in it, draw three cards instead.

Traumatize

Target player mills half their library, rounded down.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.