Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Dramatic Reversal

Untap all nonland permanents you control.

Leap

Target creature gains flying until end of turn.
Draw a card.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Surge of Brilliance

Paradox — Draw a card for each spell you've cast this turn from anywhere other than your hand.
Foretell {1}{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.)

Sejiri Glacier

Sejiri Shelter

Target creature you control gains protection from the color of your choice until end of turn.

Sejiri Shelter // Sejiri Glacier

Witch-Blessed Meadow

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {W}.

Witch Enchanter

When this creature enters, destroy target artifact or enchantment an opponent controls.

Witch Enchanter // Witch-Blessed Meadow

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.

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 token: Add one mana of any color.")

Sapphire Charm

Choose one —
• Target player draws a card at the beginning of the next turn's upkeep.
• Target creature gains flying until end of turn.
• Target creature an opponent controls phases out. (While it's phased out, it's treated as though it doesn't exist. It phases in before its controller untaps during their next untap step.)

Demolition Field

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

Snap

Return target creature to its owner's hand. Untap up to two lands.

Impulse

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

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard this card: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Geralf, the Fleshwright

Whenever you cast a spell during your turn other than your first spell that turn, create a 2/2 blue and black Zombie Rogue creature token.
Whenever a Zombie you control enters, put a +1/+1 counter on it for each other Zombie that entered the battlefield under your control this turn.

Monastery Mentor

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, create a 1/1 white Monk creature token with prowess.

Glacial Fortress

This land enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Azorius Signet

Angelic Intervention

Target creature or planeswalker you control gains protection from colorless or from the color of your choice until end of turn. If it's a creature, put a +1/+1 counter on it. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything with that quality.)

Silundi Isle

Silundi Vision

Look at the top six cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Silundi Vision // Silundi Isle

Rally the Monastery

This spell costs {2} less to cast if you've cast another spell this turn.
Choose one —
• Create two 1/1 white Monk creature tokens with prowess.
• Up to two target creatures you control each get +2/+2 until end of turn.
• Destroy target creature with power 4 or greater.

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Plaza of Heroes

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell.
{T}: Add one mana of any color among legendary permanents you control.
{3}, {T}, Exile this land: Target legendary creature gains hexproof and indestructible until end of turn.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Urza, Lord Protector

Artifact, instant, and sorcery spells you cast cost {1} less to cast.
{7}: If you both own and control Urza, Lord Protector and an artifact named The Mightstone and Weakstone, exile them, then meld them into Urza, Planeswalker. Activate only as a sorcery.

Archmage of Runes

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, draw a card.

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Curate

Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Draw a card.

Thought Scour

Target player mills two cards.
Draw a card.

Misty Rainforest

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.

Shelter

Target creature you control gains protection from the color of your choice until end of turn.
Draw a card.

Unsubstantiate

Return target spell or creature to its owner's hand.

Razorgrass Field

Razorgrass Ambush

Razorgrass Ambush deals 3 damage to target attacking or blocking creature.

Razorgrass Ambush // Razorgrass Field

Moment of Truth

Look at the top three cards of your library. Put one of those cards into your hand, one into your graveyard, and one on the bottom of your library.

Case of the Ransacked Lab

Instant and sorcery spells you cast cost {1} less to cast.
To solve — You've cast four or more instant and sorcery spells this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you cast an instant or sorcery spell, draw a card.

Shadow Rift

Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)
Draw a card.

Meticulous Archive

({T}: Add {W} or {U}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

Sapphire Medallion

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

Floodfarm Verge

{T}: Add {W}.
{T}: Add {U}. Activate only if you control a Plains or an Island.

Winds of Rebuke

Return target nonland permanent to its owner's hand. Each player mills two cards.

Giver of Runes

{T}: Another target creature you control gains protection from colorless or from the color of your choice until end of turn.

Plains

Thunderclap Drake

Flying
Instant and sorcery spells you cast cost {1} less to cast.
{2}{U}, Sacrifice this creature: When you next cast an instant or sorcery spell this turn, copy it for each time you've cast your commander from the command zone this game. You may choose new targets for the copies.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

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.

Murmuring Mystic

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

Wing It

Target creature gets +2/+2 until end of turn. Put a flying counter on it. Scry 1.

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. This land deals 1 damage to you.

Flooded Strand

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Reliquary Tower

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

Voracious Bibliophile

Flying, vigilance
Whenever you cast a spell with one or more targets, draw that many cards.

Unauthorized Exit

Return target nonland permanent to its owner's hand. Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Island

Disenchant

Updraft

Target creature gains flying until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Valorous Stance

Choose one —
• Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)
• Destroy target creature with toughness 4 or greater.

Deserted Beach

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Soporific Springs

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Sink into Stupor

Return target spell or nonland permanent an opponent controls to its owner's hand.

Sink into Stupor // Soporific Springs

Final Showdown

Spree (Choose one or more additional costs.)
+ {1} — All creatures lose all abilities until end of turn.
+ {1} — Choose a creature you control. It gains indestructible until end of turn.
+ {3}{W}{W} — Destroy all creatures.

Reflecting Pool

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

Arcane Lighthouse

{T}: Add {C}.
{1}, {T}: Until end of turn, creatures your opponents control lose hexproof and shroud and can't have hexproof or shroud.

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.

Prairie Stream

({T}: Add {W} or {U}.)
This land enters tapped unless you control two or more basic lands.

Geistwave

Return target nonland permanent to its owner's hand. If you controlled that permanent, draw a card.

Roaming Throne

Ward {2}
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Swords to Plowshares

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

Command Tower

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

Turnabout

Choose artifact, creature, or land. Tap all untapped permanents of the chosen type target player controls, or untap all tapped permanents of that type that player controls.

Ondu Skyruins

Ondu Inversion

Ondu Inversion // Ondu Skyruins

Sudden Substitution

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Exchange control of target noncreature spell and target creature. Then the spell's controller may choose new targets for it.

Arcane Signet

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

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.")

Zethi, Arcane Blademaster

Multikicker {W/U}
When Zethi, Arcane Blademaster enters, exile up to X target instant cards from your graveyard, where X is the number of times Zethi was kicked. Put a kick counter on each of them.
Whenever Zethi attacks, copy each exiled card you own with a kick counter on it. You may cast the copies.

Sol Ring

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Perplexing Test

Choose one —
• Return all creature tokens to their owners' hands.
• Return all nontoken creatures to their owners' hands.

Lightfoot Technique

Put a +1/+1 counter on target creature. It gains flying and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

You Come to a River

Choose one —
• Fight the Current — Return target nonland permanent to its owner's hand.
• Find a Crossing — Target creature gets +1/+0 until end of turn and can't be blocked this turn.