Whir of Invention

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Plains

Lavinia, Azorius Renegade

Each opponent can't cast noncreature spells with mana value greater than the number of lands that player controls.
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Portable Hole

When Portable Hole enters, exile target nonland permanent an opponent controls with mana value 2 or less until Portable Hole leaves the battlefield.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

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.

Urza, Lord High Artificer

When Urza, Lord High Artificer enters, create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."
Tap an untapped artifact you control: Add {U}.
{5}: Shuffle your library, then exile the top card. Until end of turn, you may play that card without paying its mana cost.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Aether Spellbomb

{U}, Sacrifice Aether Spellbomb: Return target creature to its owner's hand.
{1}, Sacrifice Aether Spellbomb: Draw a card.

Relic of Progenitus

{T}: Target player exiles a card from their graveyard.
{1}, Exile Relic of Progenitus: Exile all graveyards. Draw a card.

Void Mirror

Whenever a player casts a spell, if no colored mana was spent to cast it, counter that spell.

Riddlesmith

Whenever you cast an artifact spell, you may draw a card. If you do, discard a card.

March of Otherworldly Light

As an additional cost to cast this spell, you may exile any number of white cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Exile target artifact, creature, or enchantment with mana value X or less.

Lion Sash

{W}: Exile target card from a graveyard. If it was a permanent card, put a +1/+1 counter on Lion Sash.
Equipped creature gets +1/+1 for each +1/+1 counter on Lion Sash.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Haywire Mite

When Haywire Mite dies, you gain 2 life.
{G}, Sacrifice Haywire Mite: Exile target noncreature artifact or noncreature enchantment.

Razortide Bridge

Razortide Bridge enters tapped.
Indestructible
{T}: Add {W} or {U}.

Island

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Metallic Rebuke

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Counter target spell unless its controller pays {3}.

Nettlecyst

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

The Mycosynth Gardens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{X}, {T}: The Mycosynth Gardens becomes a copy of target nontoken artifact you control with mana value X.

Sword of the Meek

Equipped creature gets +1/+2.
Equip {2}
Whenever a 1/1 creature enters under your control, you may return Sword of the Meek from your graveyard to the battlefield, then attach it to that creature.

Darksteel Citadel

The Stone Brain

{2}, {T}, Exile The Stone Brain: Choose a card name. Search target opponent's graveyard, hand, and library for up to four cards with that name and exile them. That player shuffles, then draws a card for each card exiled from their hand this way. Activate only as a sorcery.

Spara's Headquarters

({T}: Add {G}, {W}, or {U}.)
Spara's Headquarters enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Teferi, Time Raveler

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

Stoneforge Mystic

When Stoneforge Mystic enters, you may search your library for an Equipment card, reveal it, put it into your hand, then shuffle.
{1}{W}, {T}: You may put an Equipment card from your hand onto the battlefield.

Pithing Needle

As Pithing Needle enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Thopter Foundry

{1}, Sacrifice a nontoken artifact: Create a 1/1 blue Thopter artifact creature token with flying. You gain 1 life.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Damping Sphere

If a land is tapped for two or more mana, it produces {C} instead of any other type and amount.
Each spell a player casts costs {1} more to cast for each other spell that player has cast this turn.

Kaldra Compleat

Living weapon
Indestructible
Equipped creature gets +5/+5 and has first strike, trample, indestructible, haste, and "Whenever this creature deals combat damage to a creature, exile that creature."
Equip {7}

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Prismatic Ending

Converge — Exile target nonland permanent if its mana value is less than or equal to the number of colors of mana spent to cast this spell.

Ingenious Smith

When Ingenious Smith enters, look at the top four cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Whenever one or more artifacts you control enter, put a +1/+1 counter on Ingenious Smith. This ability triggers only once each turn.