Omen of the Sea

Flash (You may cast this spell any time you could cast an instant.)
When Omen of the Sea enters, scry 2, then draw a card.
{2}{U}, Sacrifice Omen of the Sea: 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.)

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Grand Arbiter Augustin IV

White spells you cast cost {1} less to cast.
Blue spells you cast cost {1} less to cast.
Spells your opponents cast cost {1} more to cast.

Basalt Monolith

Basalt Monolith doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap Basalt Monolith.

Frozen Aether

Artifacts, creatures, and lands your opponents control enter tapped.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Sol Ring

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Brago, King Eternal

Flying
Whenever Brago, King Eternal deals combat damage to a player, exile any number of target nonland permanents you control, then return those cards to the battlefield under their owner's control.

Dauntless Dismantler

Artifacts your opponents control enter tapped.
{X}{X}{W}, Sacrifice Dauntless Dismantler: Destroy each artifact with mana value X.

Doubling Cube

{3}, {T}: Double the amount of each type of unspent mana you have.

God-Pharaoh's Statue

Spells your opponents cast cost {2} more to cast.
At the beginning of your end step, each opponent loses 1 life.

Winter Orb

As long as Winter Orb is untapped, players can't untap more than one land during their untap steps.

Copy Artifact

You may have Copy Artifact enter as a copy of any artifact on the battlefield, except it's an enchantment in addition to its other types.

Lavinia of the Tenth

Protection from red
When Lavinia of the Tenth enters, detain each nonland permanent your opponents control with mana value 4 or less. (Until your next turn, those permanents can't attack or block and their activated abilities can't be activated.)

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Dispel

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Kismet

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Plains

Aura of Silence

Artifact and enchantment spells your opponents cast cost {2} more to cast.
Sacrifice Aura of Silence: Destroy target artifact or enchantment.

Drannith Magistrate

Your opponents can't cast spells from anywhere other than their hands.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Dovin, Hand of Control

Artifact, instant, and sorcery spells your opponents cast cost {1} more to cast.
−1: Until your next turn, prevent all damage that would be dealt to and dealt by target permanent an opponent controls.

Pearl Medallion

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

Rishadan Cutpurse

When Rishadan Cutpurse enters, each opponent sacrifices a permanent of their choice unless they pay {1}.

Urza, Lord High Artificer

When Urza, Lord High Artificer enters, create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."
Tap an untapped artifact you control: Add {U}.
{5}: Shuffle your library, then exile the top card. Until end of turn, you may play that card without paying its mana cost.

Sapphire Medallion

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

Thalia, Heretic Cathar

First strike
Creatures and nonbasic lands your opponents control enter tapped.

Rishadan Footpad

When Rishadan Footpad enters, each opponent sacrifices a permanent of their choice unless they pay {2}.

Silence

Your opponents can't cast spells this turn.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Spellseeker

When Spellseeker enters, you may search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

Elesh Norn, Mother of Machines

Vigilance
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Permanents entering don't cause abilities of permanents your opponents control to trigger.

Stasis

Players skip their untap steps.
At the beginning of your upkeep, sacrifice Stasis unless you pay {U}.

Cloud of Faeries

Flying
When Cloud of Faeries enters, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Skyclave Apparition

When Skyclave Apparition enters, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less.
When Skyclave Apparition leaves the battlefield, the exiled card's owner creates an X/X blue Illusion creature token, where X is the mana value of the exiled card.

Chrome Mox

Imprint — When Chrome Mox enters, you may exile a nonartifact, nonland card from your hand.
{T}: Add one mana of any of the exiled card's colors.

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Island

Mana Geode

When Mana Geode enters, scry 1.
{T}: Add one mana of any color.

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Pithing Needle

As Pithing Needle enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Palinchron

Flying
When Palinchron enters, untap up to seven lands.
{2}{U}{U}: Return Palinchron to its owner's hand.

Azorius Signet

Counterspell

Sky Diamond

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.