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.)

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Cerulean Wisps

Target creature becomes blue until end of turn. Untap that creature.
Draw a card.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Maze of Ith

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

Isochron Scepter

Imprint — When this artifact enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Fierce Guardianship

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

Augur of Bolas

When this creature enters, look at the top three 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 any order.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: This artifact deals 50 damage to any target.

Dream's Grip

Choose one —
• Tap target permanent.
• Untap target permanent.
Entwine {1} (Choose both if you pay the entwine cost.)

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Fleeting Distraction

Target creature gets -1/-0 until end of turn.
Draw a card.

Twisted Image

Switch target creature's power and toughness until end of turn.
Draw a card.

Shimmering Mirage

Target land becomes the basic land type of your choice until end of turn.
Draw a card.

Sludge Monster

Whenever this creature enters or attacks, put a slime counter on up to one other target creature.
Non-Horror creatures with slime counters on them lose all abilities and have base power and toughness 2/2.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Capsize

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Return target permanent to its owner's hand.

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Agent of Treachery

When this creature enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Command Beacon

{T}: Add {C}.
{T}, Sacrifice this land: Put your commander into your hand from the command zone.

Gigadrowse

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Tap target permanent.

Sakashima of a Thousand Faces

You may have Sakashima enter as a copy of another creature you control, except it has Sakashima's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Whim of Volrath

Buyback {2} (You may pay an additional {2} as you cast this spell. If you do, put this card into your hand as it resolves.)
Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another until end of turn. (For example, you may change "nonred creature" to "nongreen creature" or "plainswalk" to "swampwalk.")

Tyrite Sanctum

{T}: Add {C}.
{2}, {T}: Target legendary creature becomes a God in addition to its other types. Put a +1/+1 counter on it.
{4}, {T}, Sacrifice this land: Put an indestructible counter on target God.

Snow-Covered Island

Sunscorched Desert

When this land enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Arcane Signet

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

Bribery

Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Solve the Equation

Search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

Mystic Sanctuary

({T}: Add {U}.)
This land enters tapped unless you control three or more other Islands.
When this land enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Venser, Shaper Savant

Flash (You may cast this spell any time you could cast an instant.)
When Venser enters, return target spell or permanent to its owner's hand.

Mind Games

Buyback {2}{U} (You may pay an additional {2}{U} as you cast this spell. If you do, put this card into your hand as it resolves.)
Tap target artifact, creature, or land.

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.

Commander's Sphere

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

Thermal Flux

Choose one —
• Target nonsnow permanent becomes snow until end of turn.
• Target snow permanent isn't snow until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Aquitect's Will

Put a flood counter on target land. That land is an Island in addition to its other types for as long as it has a flood counter on it. If you control a Merfolk, draw a card.

Relm's Sketching

Create a token that's a copy of target artifact, creature, or land.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Strip Mine

{T}: Add {C}.
{T}, Sacrifice this land: Destroy target land.

Reliquary Tower

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

Decanter of Endless Water

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

Micromancer

When this creature enters, you may search your library for an instant or sorcery card with mana value 1, reveal it, put it into your hand, then shuffle.

Palinchron

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

Spark Double

You may have this creature enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Hidden Strings

You may tap or untap target permanent, then you may tap or untap another target permanent.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Knowledge Exploitation

Prowl {3}{U} (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Rogue.)
Search target opponent's library for an instant or sorcery card. You may cast that card without paying its mana cost. Then that player shuffles.

Sublime Epiphany

Choose one or more —
• Counter target spell.
• Counter target activated or triggered ability.
• Return target nonland permanent to its owner's hand.
• Create a token that's a copy of target creature you control.
• Target player draws a card.

Enervate

Tap target artifact, creature, or land.
Draw a card at the beginning of the next turn's upkeep.

Archmage Emeritus

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

Vesuvan Duplimancy

Whenever you cast a spell that targets only a single artifact or creature you control, create a token that's a copy of that artifact or creature, except it's not legendary.

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.)

Commander's Plate

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.
Equip commander {3}
Equip {5}

Clockspinning

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Choose a counter on target permanent or suspended card. Remove that counter from that permanent or card or put another of those counters on it.

Mystical Tutor

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

Glen Elendra Archmage

Flying
{U}, Sacrifice this creature: 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.)

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.

Aether Channeler

When this creature enters, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Gilded Lotus

Sapphire Medallion

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

Orvar, the All-Form

Changeling
Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents.
When a spell or ability an opponent controls causes you to discard this card, create a token that's a copy of target permanent.

Mind Bend

Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another. (For example, you may change "nonblack creature" to "nongreen creature" or "forestwalk" to "islandwalk." This effect lasts indefinitely.)

Dive Down

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Haughty Djinn

Flying
Haughty Djinn's power is equal to the number of instant and sorcery cards in your graveyard.
Instant and sorcery spells you cast cost {1} less to cast.

Twiddle

You may tap or untap target artifact, creature, or land.

Mirrormade

You may have this enchantment enter as a copy of any artifact or enchantment on the battlefield.

Fabricate

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

Ghostly Flicker

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

Rhystic Study

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

Shadow Rift

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

Cloudpost

This land enters tapped.
{T}: Add {C} for each Locus on the battlefield.

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Counterspell

Mind Flayer

Dominate Monster — When this creature enters, gain control of target creature for as long as you control this creature.

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.")

Irenicus's Vile Duplication

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.