Overtaker

{3}{U}, {T}, Discard a card: Untap target creature and gain control of it until end of turn. That creature gains haste until end of turn.

Hive Mind

Whenever a player casts an instant or sorcery spell, each other player copies that spell. Each of those players may choose new targets for their copy.

Govern the Guildless

Gain control of target monocolored creature.
Forecast — {1}{U}, Reveal Govern the Guildless from your hand: Target creature becomes the color or colors of your choice until end of turn. (Activate only during your upkeep and only once each turn.)

Ertai's Meddling

X can't be 0.
Target spell's controller exiles it with X delay counters on it.
At the beginning of each of that player's upkeeps, if that card is exiled, remove a delay counter from it. If the card has no delay counters on it, the player puts it onto the stack as a copy of the original spell.

Copy Enchantment

You may have Copy Enchantment enter as a copy of any enchantment on the battlefield.

Callous Oppressor

You may choose not to untap Callous Oppressor during your untap step.
As Callous Oppressor enters, an opponent chooses a creature type.
{T}: Gain control of target creature that isn't of the chosen type for as long as Callous Oppressor remains tapped.

Mystifying Maze

{T}: Add {C}.
{4}, {T}: Exile target attacking creature an opponent controls. At the beginning of the next end step, return it to the battlefield tapped under its owner's control.

Legacy's Allure

At the beginning of your upkeep, you may put a treasure counter on Legacy's Allure.
Sacrifice Legacy's Allure: Gain control of target creature with power less than or equal to the number of treasure counters on Legacy's Allure. (This effect lasts indefinitely.)

Caged Sun

As Caged Sun enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Followed Footsteps

Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature.

Shapesharer

Changeling (This card is every creature type.)
{2}{U}: Target Shapeshifter becomes a copy of target creature until your next turn.

Aura Graft

Gain control of target Aura that's attached to a permanent. Attach it to another permanent it can enchant.

Ray of Command

Untap target creature an opponent controls and gain control of it until end of turn. That creature gains haste until end of turn. When you lose control of the creature, tap it.

Thunderheads

Replicate {2}{U} (When you cast this spell, copy it for each time you paid its replicate cost.)
Create a 3/3 blue Weird creature token with defender and flying. Exile it at the beginning of the next end step.

Kederekt Leviathan

When Kederekt Leviathan enters, return all other nonland permanents to their owners' hands.
Unearth {6}{U} ({6}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

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.)

Shapeshifter's Marrow

At the beginning of each opponent's upkeep, that player reveals the top card of their library. If it's a creature card, the player puts the card into their graveyard and Shapeshifter's Marrow becomes a copy of that card. (If it does, it loses this ability.)

Vesuvan Doppelganger

You may have Vesuvan Doppelganger enter as a copy of any creature on the battlefield, except it doesn't copy that creature's color and it has "At the beginning of your upkeep, you may have this creature become a copy of target creature, except it doesn't copy that creature's color and it has this ability."

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

Voidmage Husher

Flash (You may cast this spell any time you could cast an instant.)
When Voidmage Husher enters, counter target activated ability. (Mana abilities can't be targeted.)
Whenever you cast a spell, you may return Voidmage Husher to its owner's hand.

Body Double

You may have Body Double enter as a copy of any creature card in a graveyard.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Vesuvan Shapeshifter

As Vesuvan Shapeshifter enters or is turned face up, you may choose another creature on the battlefield. If you do, until Vesuvan Shapeshifter is turned face down, it becomes a copy of that creature, except it has "At the beginning of your upkeep, you may turn this creature face down."
Morph {1}{U}

Master Thief

When Master Thief enters, gain control of target artifact for as long as you control Master Thief.

Reliquary Tower

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

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.

Charisma

Enchant creature
Whenever enchanted creature deals damage to a creature, gain control of the other creature for as long as Charisma remains on the battlefield.

Hindering Touch

Counter target spell unless its controller pays {2}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Ghost Quarter

{T}: Add {C}.
{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Halimar Depths

Halimar Depths enters tapped.
When Halimar Depths enters, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Island

Gather Specimens

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

Mischievous Quanar

{3}{U}{U}: Turn Mischievous Quanar face down.
Morph {1}{U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Mischievous Quanar is turned face up, copy target instant or sorcery spell. You may choose new targets for that copy.

Riptide Entrancer

Whenever Riptide Entrancer deals combat damage to a player, you may sacrifice it. If you do, gain control of target creature that player controls. (This effect lasts indefinitely.)
Morph {U}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Magus of the Unseen

{1}{U}, {T}: Untap target artifact an opponent controls and gain control of it until end of turn. It gains haste until end of turn. When you lose control of the artifact, tap it.

Echo Mage

Level up {1}{U} ({1}{U}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 2-3
2/4
{U}{U}, {T}: Copy target instant or sorcery spell. You may choose new targets for the copy.
LEVEL 4+
2/5
{U}{U}, {T}: Copy target instant or sorcery spell twice. You may choose new targets for the copies.

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.

Quicksilver Gargantuan

You may have Quicksilver Gargantuan enter as a copy of any creature on the battlefield, except it's 7/7.

Spellweaver Volute

Enchant instant card in a graveyard
Whenever you cast a sorcery spell, copy the enchanted instant card. You may cast the copy without paying its mana cost. If you do, exile the enchanted card and attach Spellweaver Volute to another instant card in a graveyard.

Armillary Sphere

{2}, {T}, Sacrifice Armillary Sphere: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Jace's Ingenuity

Cackling Counterpart

Create a token that's a copy of target creature you control.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control Roil Elemental.

Empress Galina

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

Unstable Shapeshifter

Whenever another creature enters, Unstable Shapeshifter becomes a copy of that creature, except it has this ability.

Cultural Exchange

Choose any number of creatures target player controls. Choose the same number of creatures another target player controls. Those players exchange control of those creatures. (This effect lasts indefinitely.)

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.

Captivating Glance

Enchant creature
At the beginning of your end step, clash with an opponent. If you win, gain control of enchanted creature. Otherwise, that player gains control of enchanted creature. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Twincast

Copy target instant or sorcery spell. You may choose new targets for the copy.

Sphinx Ambassador

Flying
Whenever Sphinx Ambassador deals combat damage to a player, search that player's library for a card, then that player chooses a card name. If you searched for a creature card that doesn't have that name, you may put it onto the battlefield under your control. Then that player shuffles.

Volition Reins

Enchant permanent
When Volition Reins enters, if enchanted permanent is tapped, untap it.
You control enchanted permanent.

Train of Thought

Replicate {1}{U} (When you cast this spell, copy it for each time you paid its replicate cost.)
Draw a card.

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.

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.)

Trinket Mage

When Trinket Mage enters, 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.

Cryptoplasm

At the beginning of your upkeep, you may have Cryptoplasm become a copy of another target creature, except it has this ability.

Renegade Doppelganger

Whenever another creature you control enters, you may have Renegade Doppelganger become a copy of that creature until end of turn. (If it does, it loses this ability for the rest of the turn.)

Dominate

Gain control of target creature with mana value X or less.

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.

Chamber of Manipulation

Enchant land
Enchanted land has "{T}, Discard a card: Gain control of target creature until end of turn."

Telemin Performance

Target opponent reveals cards from the top of their library until they reveal a creature card. That player puts all noncreature cards revealed this way into their graveyard, then you put the creature card onto the battlefield under your control.

Phyrexian Ingester

Imprint — When Phyrexian Ingester enters, you may exile target nontoken creature.
Phyrexian Ingester gets +X/+Y, where X is the exiled creature card's power and Y is its toughness.

Blue Sun's Zenith

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

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.

Darksteel Ingot

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

Flow of Ideas

Knowledge Pool

Imprint — When Knowledge Pool enters, each player exiles the top three cards of their library.
Whenever a player casts a spell from their hand, that player exiles it. If the player does, they may cast a spell from among other cards exiled with Knowledge Pool without paying its mana cost.

Muse Vessel

{3}, {T}: Target player exiles a card from their hand. Activate only as a sorcery.
{1}: Choose a card exiled with Muse Vessel. You may play that card this turn.

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."