Watcher for Tomorrow

Hideaway 4 (When this creature enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Watcher for Tomorrow enters the battlefield tapped.
When Watcher for Tomorrow leaves the battlefield, put the exiled card into its owner's hand.

Dack Fayden

+1: Target player draws two cards, then discards two cards.
−2: Gain control of target artifact.
−6: You get an emblem with "Whenever you cast a spell that targets one or more permanents, gain control of those permanents."

Snow-Covered Island

Mystical Tutor

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

Evacuation

Return all creatures to their owners' hands.

Serum Visions

Sunken Ruins

{T}: Add {C}.
{U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

Apprentice Necromancer

{B}, {T}, Sacrifice Apprentice Necromancer: Return target creature card from your graveyard to the battlefield. That creature gains haste. At the beginning of the next end step, sacrifice it.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Myriad Landscape

Myriad Landscape enters the battlefield tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Venser, Shaper Savant

Flash
When Venser, Shaper Savant enters the battlefield, return target spell or permanent to its owner's hand.

Thassa's Oracle

When Thassa's Oracle enters the battlefield, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Sol Ring

Snow-Covered Mountain

Havengul Lich

{1}: You may cast target creature card in a graveyard this turn. When you cast it this turn, Havengul Lich gains all activated abilities of that card until end of turn.

Galecaster Colossus

Tap an untapped Wizard you control: Return target nonland permanent you don't control to its owner's hand.

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Glen Elendra Archmage

Flying
{U}, Sacrifice Glen Elendra Archmage: Counter target noncreature spell.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Command Tower

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

Fetid Pools

({T}: Add {U} or {B}.)
Fetid Pools enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

Inalla, Archmage Ritualist

Eminence — Whenever another nontoken Wizard enters the battlefield under your control, if Inalla, Archmage Ritualist is in the command zone or on the battlefield, you may pay {1}. If you do, create a token that's a copy of that Wizard. The token gains haste. Exile it at the beginning of the next end step.
Tap five untapped Wizards you control: Target player loses 7 life.

Fellwar Stone

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

Izzet Signet

Darkslick Shores

Darkslick Shores enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {U} or {B}.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent or discards a card.

Sulfur Falls

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

Salvager of Secrets

When Salvager of Secrets enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Bojuka Bog

Bojuka Bog enters the battlefield tapped.
When Bojuka Bog enters the battlefield, exile target player's graveyard.
{T}: Add {B}.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Twinflame

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Choose any number of target creatures you control. For each of them, create a token that's a copy of that creature, except it has haste. Exile those tokens at the beginning of the next end step.

Blue Sun's Zenith

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

Brainstorm

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

Dark Petition

Search your library for a card, put that card into your hand, then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, add {B}{B}{B}.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Dimir Signet

Canyon Slough

({T}: Add {B} or {R}.)
Canyon Slough enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.

Spirebluff Canal

Spirebluff Canal enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.

Dragonskull Summit

Dragonskull Summit enters the battlefield tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Izzet Chronarch

When Izzet Chronarch enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Devastation Tide

Return all nonland permanents to their owners' hands.
Miracle {1}{U} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Trophy Mage

When Trophy Mage enters the battlefield, you may search your library for an artifact card with mana value 3, reveal it, put it into your hand, then shuffle.

Bloodline Necromancer

Lifelink
When Bloodline Necromancer enters the battlefield, you may return target Vampire or Wizard creature card from your graveyard to the battlefield.

Barren Moor

Barren Moor enters the battlefield tapped.
{T}: Add {B}.
Cycling {B} ({B}, Discard this card: Draw a card.)

Burnished Hart

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

Dockside Extortionist

When Dockside Extortionist enters the battlefield, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Panharmonicon

If an artifact or creature entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Arcane Signet

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

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.")

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Sea Gate Oracle

When Sea Gate Oracle enters the battlefield, 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.

Dualcaster Mage

Flash
When Dualcaster Mage enters the battlefield, copy target instant or sorcery spell. You may choose new targets for the copy.

Counterspell

Talisman of Creativity

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

Talisman of Dominance

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

Spellseeker

When Spellseeker enters the battlefield, 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.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Trinket Mage

When Trinket Mage enters the battlefield, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Mistbind Clique

Flash
Flying
Champion a Faerie (When this enters the battlefield, sacrifice it unless you exile another Faerie you control. When this leaves the battlefield, that card returns to the battlefield.)
When a Faerie is championed with Mistbind Clique, tap all lands target player controls.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Exotic Orchard

Drowned Catacomb

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Snow-Covered Swamp

Lonely Sandbar

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

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Basalt Monolith

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

Narset, Parter of Veils

Each opponent can't draw more than one card each turn.
−2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Forgotten Cave

Forgotten Cave enters the battlefield tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

Windfall

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

Timestream Navigator

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
{2}{U}{U}, {T}, Put Timestream Navigator on the bottom of its owner's library: Take an extra turn after this one. Activate only if you have the city's blessing.

Snapcaster Mage

Flash
When Snapcaster Mage enters the battlefield, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Ashnod's Altar

Patron Wizard

Tap an untapped Wizard you control: Counter target spell unless its controller pays {1}.

Final Iteration

Flying
Wizards you control get +2/+1 and have flying.
Whenever you cast an instant or sorcery spell, create a 1/1 blue Human Wizard creature token.

Docent of Perfection

Flying
Whenever you cast an instant or sorcery spell, create a 1/1 blue Human Wizard creature token. Then if you control three or more Wizards, transform Docent of Perfection.

Docent of Perfection // Final Iteration

Darksteel Ingot

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

Azami, Lady of Scrolls

Tap an untapped Wizard you control: Draw a card.

Vedalken Aethermage

Flash (You may cast this spell any time you could cast an instant.)
When Vedalken Aethermage enters the battlefield, return target Sliver to its owner's hand.
Wizardcycling {3} ({3}, Discard this card: Search your library for a Wizard card, reveal it, put it into your hand, then shuffle.)

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Wanderwine Prophets

Champion a Merfolk (When this enters the battlefield, sacrifice it unless you exile another Merfolk you control. When this leaves the battlefield, that card returns to the battlefield.)
Whenever Wanderwine Prophets deals combat damage to a player, you may sacrifice a Merfolk. If you do, take an extra turn after this one.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Archaeomancer

When Archaeomancer enters the battlefield, return target instant or sorcery card from your graveyard to your hand.