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.)

Clever Impersonator

You may have Clever Impersonator enter as a copy of any nonland permanent on the battlefield.

Agent of Treachery

When Agent of Treachery 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.

Memnarch

{1}{U}{U}: Target permanent becomes an artifact in addition to its other types. (This effect lasts indefinitely.)
{3}{U}: Gain control of target artifact. (This effect lasts indefinitely.)

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.

Gilded Drake

Flying
When Gilded Drake enters, exchange control of Gilded Drake and up to one target creature an opponent controls. If you don't or can't make an exchange, sacrifice Gilded Drake. This ability still resolves if its target becomes illegal.

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Bribery

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

Sakashima the Impostor

You may have Sakashima the Impostor enter as a copy of any creature on the battlefield, except its name is Sakashima the Impostor, it's legendary in addition to its other types, and it has "{2}{U}{U}: Return this creature to its owner's hand at the beginning of the next end step."

Sapphire Medallion

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

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Control Magic

Enchant creature
You control enchanted creature.

Leyline of Singularity

If Leyline of Singularity is in your opening hand, you may begin the game with it on the battlefield.
All nonland permanents are legendary.

Castle Vantress

Castle Vantress enters tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for the player.)

Mass Manipulation

Gain control of X target creatures and/or planeswalkers.

Empress Galina

{U}{U}, {T}: Gain control of target legendary permanent. (This effect lasts indefinitely.)

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Gather Specimens

If a creature would enter the battlefield under an opponent's control this turn, it enters under your control instead.

Arcane Signet

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

Torrential Gearhulk

Flash
When Torrential Gearhulk enters, you may cast target instant card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Illusionist's Bracers

Whenever an ability of equipped creature is activated, if it isn't a mana ability, copy that ability. You may choose new targets for the copy.
Equip {3}

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.

Rite of Replication

Kicker {5} (You may pay an additional {5} as you cast this spell.)
Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

Helm of Possession

You may choose not to untap Helm of Possession during your untap step.
{2}, {T}, Sacrifice a creature: Gain control of target creature for as long as you control Helm of Possession and Helm of Possession remains tapped.

Mystic Sanctuary

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

Thada Adel, Acquisitor

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Thada Adel, Acquisitor deals combat damage to a player, search that player's library for an artifact card and exile it. Then that player shuffles. Until end of turn, you may play that card.

Gilded Lotus

Keiga, the Tide Star

Flying
When Keiga, the Tide Star dies, gain control of target creature.

Mystical Tutor

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

Spelljack

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. You may play it without paying its mana cost for as long as it remains exiled. (If it has X in its mana cost, X is 0.)

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Counterspell

Faerie Artisans

Flying
Whenever a nontoken creature an opponent controls enters, create a token that's a copy of that creature except it's an artifact in addition to its other types. Then exile all other tokens created with Faerie Artisans.

Fellwar Stone

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

Rhystic Study

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

Kira, Great Glass-Spinner

Flying
Creatures you control have "Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability."

Confiscate

Enchant permanent
You control enchanted permanent.

Sakashima's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Target opponent chooses a creature they control. You gain control of it.
• Choose a creature you control. Each other creature you control becomes a copy of that creature until end of turn.

Treachery

Enchant creature
When Treachery enters, untap up to five lands.
You control enchanted creature.

Archmage's Charm

Choose one —
• Counter target spell.
• Target player draws two cards.
• Gain control of target nonland permanent with mana value 1 or less.

Inevitable Betrayal

Suspend 3—{1}{U}{U} (Rather than cast this card from your hand, pay {1}{U}{U} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Brainstorm

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

Fierce Guardianship

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

Vedalken Shackles

You may choose not to untap Vedalken Shackles during your untap step.
{2}, {T}: Gain control of target creature with power less than or equal to the number of Islands you control for as long as Vedalken Shackles remains tapped.

Island

Thran Dynamo

Acquire

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

Blatant Thievery

For each opponent, gain control of target permanent that player controls.

Desertion

Counter target spell. If an artifact or creature spell is countered this way, put that card onto the battlefield under your control instead of into its owner's graveyard.

Sakashima of a Thousand Faces

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

Sol Ring

Propaganda

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

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.

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.")

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Aethersnatch

Gain control of target spell. You may choose new targets for it. (If that spell becomes a permanent, it enters under your control.)

Commandeer

You may exile two blue cards from your hand rather than pay this spell's mana cost.
Gain control of target noncreature spell. You may choose new targets for it. (If that spell is an artifact, enchantment, or planeswalker, the permanent enters under your control.)

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Mirrormade

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

Lightning Greaves

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

Minamo, School at Water's Edge

{T}: Add {U}.
{U}, {T}: Untap target legendary permanent.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Fumble

Return target creature to its owner's hand. Gain control of all Auras and Equipment that were attached to it, then attach them to another creature.

Thousand-Year Elixir

You may activate abilities of creatures you control as though those creatures had haste.
{1}, {T}: Untap target creature.

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.

Stunt Double

Flash
You may have Stunt Double enter as a copy of any creature on the battlefield.

Thieving Skydiver

Kicker {X}. X can't be 0. (You may pay an additional {X} as you cast this spell.)
Flying
When Thieving Skydiver enters, if it was kicked, gain control of target artifact with mana value X or less. If that artifact is an Equipment, attach it to Thieving Skydiver.