Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Boompile

{T}: Flip a coin. If you win the flip, destroy all nonland permanents.

Mirrorworks

Whenever another nontoken artifact you control enters, you may pay {2}. If you do, create a token that's a copy of that artifact.

Hulking Metamorph

Prototype {2}{U}{U} — 3/3 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
You may have Hulking Metamorph enter as a copy of an artifact or creature you control, except it's an artifact creature in addition to its other types, and its power and toughness are equal to Hulking Metamorph's power and toughness.

Fellwar Stone

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

Oblivion Stone

{4}, {T}: Put a fate counter on target permanent.
{5}, {T}, Sacrifice Oblivion Stone: Destroy each nonland permanent without a fate counter on it, then remove all fate counters from all permanents.

Darksteel Monolith

Indestructible
Once each turn, you may pay {0} rather than pay the mana cost for a colorless spell you cast from your hand.

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Shimmer Myr

Flash
You may cast artifact spells as though they had flash.

Coveted Jewel

When Coveted Jewel enters, draw three cards.
{T}: Add three mana of any one color.
Whenever one or more creatures an opponent controls attack you and aren't blocked, that player draws three cards and gains control of Coveted Jewel. Untap it.

Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Thought Monitor enters, draw two cards.

Tidal Barracuda

Any player may cast spells as though they had flash.
Your opponents can't cast spells during your turn.

Mind Stone

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

Drafna, Founder of Lat-Nam

{1}{U}: Return target artifact you control to its owner's hand.
{3}, {T}: Copy target artifact spell you control. (The copy becomes a token.)

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Master Transmuter

{U}, {T}, Return an artifact you control to its owner's hand: You may put an artifact card from your hand onto the battlefield.

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

March of Swirling Mist

As an additional cost to cast this spell, you may exile any number of blue cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Up to X target creatures phase out. (While they're phased out, they're treated as though they don't exist. Each one phases in before its controller untaps during their next untap step.)

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Crawlspace

No more than two creatures can attack you each combat.

Gilded Lotus

Etherium Sculptor

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

Marina Vendrell's Grimoire

When Marina Vendrell's Grimoire enters, if you cast it, draw five cards.
You have no maximum hand size and don't lose the game for having 0 or less life.
Whenever you gain life, draw that many cards.
Whenever you lose life, discard that many cards. Then if you have no cards in hand, you lose the game.

Memory Jar

{T}, Sacrifice Memory Jar: Each player exiles all cards from their hand face down and draws seven cards. At the beginning of the next end step, each player discards their hand and returns to their hand each card they exiled this way.

Final-Word Phantom

Flash
Flying
During each opponent's end step, you may cast spells as though they had flash.

Sword of the Paruns

As long as equipped creature is tapped, tapped creatures you control get +2/+0.
As long as equipped creature is untapped, untapped creatures you control get +0/+2.
{3}: You may tap or untap equipped creature.
Equip {3}

Mirran Spy

Flying
Whenever you cast an artifact spell, you may untap target creature.

Semblance Anvil

Imprint — When Semblance Anvil enters, you may exile a nonland card from your hand.
Spells you cast that share a card type with the exiled card cost {2} less to cast.

Tangle Wire

Fading 4 (This artifact enters with four fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
At the beginning of each player's upkeep, that player taps an untapped artifact, creature, or land they control for each fade counter on Tangle Wire.

Vedalken Orrery

You may cast spells as though they had flash.

Sol Ring

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.

Arcane Signet

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

Nevinyrral's Disk

Nevinyrral's Disk enters tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

Sculpting Steel

You may have Sculpting Steel enter as a copy of any artifact on the battlefield.

Liberator, Urza's Battlethopter

Flash
Flying
You may cast colorless spells and artifact spells as though they had flash.
Whenever you cast a spell, if the amount of mana spent to cast that spell is greater than Liberator, Urza's Battlethopter's power, put a +1/+1 counter on Liberator.

Skittering Cicada

Flash
You may cast colorless spells as though they had flash.
Whenever you cast a colorless spell, until end of turn, Skittering Cicada gains trample and gets +X/+X, where X is that spell's mana value.

Marvin, Murderous Mimic

Marvin, Murderous Mimic has all activated abilities of creatures you control that don't have the same name as this creature.

Karn's Sylex

Karn's Sylex enters tapped.
Players can't pay life to cast spells or to activate abilities that aren't mana abilities.
{X}, {T}, Exile Karn's Sylex: Destroy each nonland permanent with mana value X or less. Activate only as a sorcery.

Glaring Fleshraker

Whenever you cast a colorless spell, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this creature: Add {C}."
Whenever another colorless creature you control enters, Glaring Fleshraker deals 1 damage to each opponent.

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.

Island

Skyclave Relic

Kicker {3}
Indestructible
When Skyclave Relic enters, if it was kicked, create two tapped tokens that are copies of Skyclave Relic.
{T}: Add one mana of any color.

Foundry Inspector

Thran Dynamo

Wrong Turn

Target opponent gains control of target creature. (If an attacking or blocking creature changes controllers, it's removed from combat.)