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.

Nullmage Shepherd

Tap four untapped creatures you control: Destroy target artifact or enchantment.

Incubation Druid

{T}: Add one mana of any type that a land you control could produce. If Incubation Druid has a +1/+1 counter on it, add three mana of that type instead.
{3}{G}{G}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)

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.

Glissa Sunseeker

First strike
{T}: Destroy target artifact if its mana value is equal to the amount of unspent mana you have.

Llanowar Elves

Bane of Progress

When Bane of Progress enters, destroy all artifacts and enchantments. Put a +1/+1 counter on Bane of Progress for each permanent destroyed this way.

Elvish Mystic

Mycosynth Lattice

All permanents are artifacts in addition to their other types.
All cards that aren't on the battlefield, spells, and permanents are colorless.
Players may spend mana as though it were mana of any color.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on Devoted Druid: Untap Devoted Druid.

Fyndhorn Elves

Liquimetal Coating

{T}: Target permanent becomes an artifact in addition to its other types until end of turn.