Stenn, Paranoid Partisan

As Stenn enters, choose a card type other than creature or land.
Spells you cast of the chosen type cost {1} less to cast.
{1}{W}{U}: Exile Stenn. Return it to the battlefield under its owner's control at the beginning of the next end step.

Lantern of Revealing

{T}: Add one mana of any color.
{4}, {T}: Look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, you may put it on the bottom of your library.

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.

Braids, Conjurer Adept

At the beginning of each player's upkeep, that player may put an artifact, creature, or land card from their hand onto the battlefield.

Emmessi Tome

{5}, {T}: Draw two cards, then discard a card.

Boom Box

{6}, {T}, Sacrifice this artifact: Destroy up to one target artifact, up to one target creature, and up to one target land.

Urza, Lord Protector

Artifact, instant, and sorcery spells you cast cost {1} less to cast.
{7}: If you both own and control Urza, Lord Protector and an artifact named The Mightstone and Weakstone, exile them, then meld them into Urza, Planeswalker. Activate only as a sorcery.

Aladdin's Lamp

{X}, {T}: The next time you would draw a card this turn, instead look at the top X cards of your library, put all but one of them on the bottom of your library in a random order, then draw a card. X can't be 0.

Birthing Boughs

{4}, {T}: Create a 2/2 colorless Shapeshifter creature token with changeling. (It is every creature type.)

Clifftop Retreat

This land enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Copper Gnomes

{4}, Sacrifice this creature: 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.)

Cogwork Assembler

{7}: Create a token that's a copy of target artifact. That token gains haste. Exile it at the beginning of the next end step.

Arcum Dagsson

{T}: Target artifact creature's controller sacrifices it. That player may search their library for a noncreature artifact card, put it onto the battlefield, then shuffle.

Folio of Fancies

Players have no maximum hand size.
{X}{X}, {T}: Each player draws X cards.
{2}{U}, {T}: Each opponent mills cards equal to the number of cards in their hand.

Bloodtallow Candle

{6}, {T}, Sacrifice this artifact: Target creature gets -5/-5 until end of turn.

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Planar Bridge

{8}, {T}: Search your library for a permanent card, put it onto the battlefield, then shuffle.

Nahiri's Wrath

As an additional cost to cast this spell, discard X cards.
Nahiri's Wrath deals damage equal to the total mana value of the discarded cards to each of up to X target creatures and/or planeswalkers.

Mystic Monastery

This land enters tapped.
{T}: Add {U}, {R}, or {W}.

Starnheim Courser

Flying
Artifact and enchantment spells you cast cost {1} less to cast.

Saheeli, Filigree Master

+1: Scry 1. You may tap an untapped artifact you control. If you do, draw a card.
−2: Create two 1/1 colorless Thopter artifact creature tokens with flying. They gain haste until end of turn.
−4: You get an emblem with "Artifact creatures you control get +1/+1" and "Artifact spells you cast cost {1} less to cast."

Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Decimator Web

{4}, {T}: Target opponent loses 2 life, gets a poison counter, then mills six cards.

Plains

Bosh, Iron Golem

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

Foundry Inspector

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

Mountain

Arcane Signet

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

Sol Ring

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.

Dreamstone Hedron

{T}: Add {C}{C}{C}.
{3}, {T}, Sacrifice this artifact: Draw three cards.

Island

Candles of Leng

{4}, {T}: Reveal the top card of your library. If it has the same name as a card in your graveyard, put it into your graveyard. Otherwise, draw a card.

Bonder's Ornament

{T}: Add one mana of any color.
{4}, {T}: Each player who controls a permanent named Bonder's Ornament draws a card.

Chaos Wand

{4}, {T}: Target opponent exiles cards from the top of their library until they exile an instant or sorcery card. You may cast that card without paying its mana cost. Then put the exiled cards that weren't cast this way on the bottom of that library in a random order.

The Mightstone and Weakstone

When The Mightstone and Weakstone enters, choose one —
• Draw two cards.
• Target creature gets -5/-5 until end of turn.
{T}: Add {C}{C}. This mana can't be spent to cast nonartifact spells.
(Melds with Urza, Lord Protector.)

Jayemdae Tome

Zirda, the Dawnwaker

Companion — Each permanent card in your starting deck has an activated ability. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Abilities you activate that aren't mana abilities cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{1}, {T}: Target creature can't block this turn.

Prairie Stream

({T}: Add {W} or {U}.)
This land enters tapped unless you control two or more basic lands.

Azorius Signet

Apex Observatory

This artifact enters tapped. As it enters, choose a card type shared among two exiled cards used to craft it.
{T}: The next spell you cast this turn of the chosen type can be cast without paying its mana cost.

Eye of Ojer Taq

{T}: Add one mana of any color.
Craft with two that share a card type {6} ({6}, Exile this artifact, Exile the two from among other permanents you control and/or cards from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Eye of Ojer Taq // Apex Observatory

Galvanic Key

Automated Artificer

{T}: Add {C}. Spend this mana only to activate an ability or cast an artifact spell.

Assert Authority

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Boros Signet

Thran Temporal Gateway

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

Glacial Fortress

This land enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Basalt Monolith

This artifact doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap this artifact.

Jodah's Codex

Domain — {5}, {T}: Draw a card. This ability costs {1} less to activate for each basic land type among lands you control.

Enthusiastic Mechanaut

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

Spectator Seating

This land enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Command Tower

Book of Rass

Bhaal's Invoker

Scorching Ray — {8}: This creature deals 4 damage to each opponent.

Dynaheir, Invoker Adept

Haste
You may activate abilities of other creatures you control as though those creatures had haste.
{T}: When you next activate an ability that isn't a mana ability this turn by spending four or more mana to activate it, copy that ability. You may choose new targets for the copy.

Archway of Innovation

This land enters tapped unless you control an Island.
{T}: Add {U}.
{U}, {T}: The next spell you cast this turn has improvise. (Your artifacts can help cast that spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Artificer Class

(Gain the next level as a sorcery to add its ability.)
The first artifact spell you cast each turn costs {1} less to cast.
{1}{U}: Level 2
When this Class becomes level 2, reveal cards from the top of your library until you reveal an artifact card. Put that card into your hand and the rest on the bottom of your library in a random order.
{5}{U}: Level 3
At the beginning of your end step, create a token that's a copy of target artifact you control.

Valakut Invoker

{8}: This creature deals 3 damage to any target.

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.

Filigree Sages

Amulet of Unmaking

{5}, {T}, Exile this artifact: Exile target artifact, creature, or land. Activate only as a sorcery.

Izzet Signet

Wrath of God

Destroy all creatures. They can't be regenerated.

Akki Scrapchomper

{1}{R}, {T}, Sacrifice an artifact or land: Draw a card.

Sulfur Falls

This land enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Myr Welder

Imprint — {T}: Exile target artifact card from a graveyard.
This creature has all activated abilities of all cards exiled with it.

Jhoira, Ageless Innovator

{T}: Put two ingenuity counters on Jhoira, then you may put an artifact card with mana value X or less from your hand onto the battlefield, where X is the number of ingenuity counters on Jhoira.

Etherium Sculptor

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.

Tymora's Invoker

Ayesha Tanaka, Armorer

Whenever Ayesha Tanaka attacks, look at the top four cards of your library. You may put any number of artifact cards with mana value less than or equal to Ayesha Tanaka's power from among them onto the battlefield tapped. Put the rest on the bottom of your library in a random order.
Ayesha Tanaka can't be blocked as long as defending player controls three or more artifacts.

Aladdin's Ring

{8}, {T}: This artifact deals 4 damage to any target.

Akal Pakal, First Among Equals

At the beginning of each player's end step, if an artifact entered the battlefield under your control this turn, look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.

Training Center

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Buried Treasure

{T}, Sacrifice this artifact: Add one mana of any color.
{5}, Exile this card from your graveyard: Discover 5. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 5 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.