Cloud Key

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

Jhoira's Familiar

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

Mountain

Meteor Golem

When this creature enters, destroy target nonland permanent an opponent controls.

Ancient Stone Idol

Flash
This spell costs {1} less to cast for each attacking creature.
Trample
When this creature dies, create a 6/12 colorless Construct artifact creature token with trample.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Flameshadow Conjuring

Whenever a nontoken creature you control enters, you may pay {R}. If you do, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.

Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

Gratuitous Violence

If a creature you control would deal damage to a permanent or player, it deals double that damage instead.

Oxidda Golem

Affinity for Mountains (This spell costs {1} less to cast for each Mountain you control.)
Haste

Sanctum of Ugin

{T}: Add {C}.
Whenever you cast a colorless spell with mana value 7 or greater, you may sacrifice this land. If you do, search your library for a colorless creature card, reveal it, put it into your hand, then shuffle.

Sandstone Oracle

Flying
When this creature enters, choose an opponent. If that player has more cards in hand than you, draw cards equal to the difference.

Colfenor's Urn

Whenever a creature with toughness 4 or greater is put into your graveyard from the battlefield, you may exile it.
At the beginning of the end step, if three or more cards have been exiled with this artifact, sacrifice it. If you do, return those cards to the battlefield under their owner's control.

Su-Chi Cave Guard

Vigilance
Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
When this creature dies, add eight {C}. Until end of turn, you don't lose this mana as steps and phases end.

Darksteel Citadel

Imposing Grandeur

Each player may discard their hand and draw cards equal to the greatest mana value of a commander they own on the battlefield or in the command zone.

Cauldron of Souls

{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it 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.)

Slagstone Refinery

Whenever this artifact or another nontoken artifact you control is put into a graveyard from the battlefield or is put into exile from the battlefield, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

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.

Myr Enforcer

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Scuttling Doom Engine

This creature can't be blocked by creatures with power 2 or less.
When this creature dies, it deals 6 damage to target opponent or planeswalker.

Great Furnace

Skitterbeam Battalion

Prototype {3}{R}{R} — 2/2 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Trample, haste
When this creature enters, if you cast it, create two tokens that are copies of it.

Thran Dynamo

Tannuk, Steadfast Second

Other creatures you control have haste.
Artifact cards and red creature cards in your hand have warp {2}{R}. (You may cast a card from your hand for its warp cost. Exile that permanent at the beginning of the next end step, then you may cast it from exile on a later turn.)

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Sojourner's Companion

Affinity for artifacts
Artifact landcycling {2} ({2}, Discard this card: Search your library for an artifact land card, reveal it, put it into your hand, then shuffle.)

Metalwork Colossus

This spell costs {X} less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return this card from your graveyard to your hand.

Semblance Anvil

Imprint — When this artifact 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.

Feldon of the Third Path

{2}{R}, {T}: Create a token that's a copy of target creature card in your graveyard, except it's an artifact in addition to its other types. It gains haste. Sacrifice it at the beginning of the next end step.

Workshop Assistant

When this creature dies, return another target artifact card from your graveyard to your hand.

Reliquary Tower

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

Salvager of Ruin

Sacrifice this creature: Choose target permanent card in your graveyard that was put there from the battlefield this turn. Return it to your hand.

Quicksilver Amulet

{4}, {T}: You may put a creature card from your hand onto the battlefield.

Eden, Seat of the Sanctum

{T}: Add {C}.
{5}, {T}: Mill two cards. Then you may sacrifice this land. When you do, return another target permanent card from your graveyard to your hand.

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with this artifact to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with this artifact. It gains haste. Exile it at the beginning of the next end step.

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Return target artifact card from your graveyard to your hand.

Foundry Inspector

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

Iron Myr

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.)

Frogmyr Enforcer

Prototype {3}{R} — 2/2 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Haunted Fengraf

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Return a creature card at random from your graveyard to your hand.

Maelstrom Colossus

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Fire Diamond

This artifact enters tapped.
{T}: Add {R}.

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.

Alena, Kessig Trapper

First strike
{T}: Add an amount of {R} equal to the greatest power among creatures you control that entered this turn.
Partner (You can have two commanders if both have partner.)

Worn Powerstone

This artifact enters tapped.
{T}: Add {C}{C}.

Kurkesh, Onakke Ancient

Whenever you activate an ability of an artifact, if it isn't a mana ability, you may pay {R}. If you do, copy that ability. You may choose new targets for the copy.

Pia's Revolution

Whenever a nontoken artifact is put into your graveyard from the battlefield, return that card to your hand unless target opponent has this enchantment deal 3 damage to them.

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}

Scrap Trawler

Whenever this creature dies or another artifact you control is put into a graveyard from the battlefield, return to your hand target artifact card in your graveyard with lesser mana value.

Mishra's Self-Replicator

Whenever you cast a historic spell, you may pay {1}. If you do, create a token that's a copy of this creature. (Artifacts, legendaries, and Sagas are historic.)

Ruin Grinder

Menace
When this creature dies, each player may discard their hand and draw seven cards.
Mountaincycling {2} ({2}, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)

Sol Ring

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Neheb, the Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
At the beginning of each of your postcombat main phases, add {R} for each 1 life your opponents have lost this turn.

Thran Temporal Gateway

{4}, {T}: You may put a historic permanent card from your hand onto the battlefield. (Artifacts, legendaries, and Sagas are historic.)

Cursed Mirror

{T}: Add {R}.
As this artifact enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Myr Retriever

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Nim Deathmantle

Equipped creature gets +2/+2, has intimidate, and is a black Zombie. (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a nontoken creature is put into your graveyard from the battlefield, you may pay {4}. If you do, return that card to the battlefield and attach this Equipment to it.
Equip {4}

Palladium Myr

Adventurer's Inn

When this land enters, you gain 2 life.
{T}: Add {C}.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Secluded Starforge

{T}: Add {C}.
{2}, {T}, Tap X untapped artifacts you control: Target creature gets +X/+0 until end of turn. Activate only as a sorcery.
{5}, {T}: Create a 2/2 colorless Robot artifact creature token.

Spine of Ish Sah

When this artifact enters, destroy target permanent.
When this artifact is put into a graveyard from the battlefield, return it to its owner's hand.

Bosh, Iron Golem

Trample
{3}{R}, Sacrifice an artifact: Bosh deals damage equal to the sacrificed artifact's mana value to any target.

Manakin

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Junk Diver

Flying
When this creature dies, return another target artifact card from your graveyard to your hand.

Bonders' Enclave

{T}: Add {C}.
{3}, {T}: Draw a card. Activate only if you control a creature with power 4 or greater.

Bygone Colossus

Warp {3} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Trash for Treasure

As an additional cost to cast this spell, sacrifice an artifact.
Return target artifact card from your graveyard to the battlefield.

Lightning Greaves

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

Scarecrone

{1}, Sacrifice a Scarecrow: Draw a card.
{4}, {T}: Return target artifact creature card from your graveyard to the battlefield.

Sculpting Steel

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

Command Beacon

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

Shrine of the Forsaken Gods

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast colorless spells. Activate only if you control seven or more lands.

Spinerock Knoll

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
This land enters tapped.
{T}: Add {R}.
{R}, {T}: You may play the exiled card without paying its mana cost if an opponent was dealt 7 or more damage this turn.