Karn, the Great Creator

Activated abilities of artifacts your opponents control can't be activated.
+1: Until your next turn, up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.
−2: You may reveal an artifact card you own from outside the game or choose a face-up artifact card you own in exile. Put that card into your hand.

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.

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.

Goblin Welder

{T}: Choose target artifact a player controls and target artifact card in that player's graveyard. If both targets are still legal as this ability resolves, that player simultaneously sacrifices the artifact and returns the artifact card to the battlefield.

Goblin Engineer

When Goblin Engineer enters, you may search your library for an artifact card, put it into your graveyard, then shuffle.
{R}, {T}, Sacrifice an artifact: Return target artifact card with mana value 3 or less from your graveyard to the battlefield.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Boros Signet

Thran Dynamo

Sacred Foundry

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

Thrilling Discovery

You gain 2 life. Then you may discard two cards. If you do, draw three cards.

Saheeli's Directive

Improvise (Each artifact you tap after you're done activating mana abilities pays for {1}.)
Reveal the top X cards of your library. You may put any number of artifact cards with mana value X or less from among them onto the battlefield. Then put all cards revealed this way that weren't put onto the battlefield into your graveyard.

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.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Talisman of Conviction

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

Buried Ruin

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

Inventors' Fair

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.

Lightning Greaves

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