Carapace Forger

Metalcraft — Carapace Forger gets +2/+2 as long as you control three or more artifacts.

Wind Zendikon

Enchant land
Enchanted land is a 2/2 blue Elemental creature with flying. It's still a land.
When enchanted land dies, return that card to its owner's hand.

Great Furnace

Slagwoods Bridge

Slagwoods Bridge enters tapped.
Indestructible
{T}: Add {R} or {G}.

Forest

Commune with Spirits

Look at the top four cards of your library. You may reveal an enchantment or land card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Crusher Zendikon

Enchant land
Enchanted land is a 4/2 red Beast creature with trample. It's still a land.
When enchanted land dies, return that card to its owner's hand.

Tanglepool Bridge

Tanglepool Bridge enters tapped.
Indestructible
{T}: Add {G} or {U}.

Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

Harmonious Emergence

Enchant land you control
Enchanted land is a 4/5 green Spirit creature with vigilance and haste. It's still a land.
If enchanted land would be destroyed, instead sacrifice Harmonious Emergence and that land gains indestructible until end of turn.

Thoughtcast

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

Seat of the Synod

Tree of Tales

Cleansing Wildfire

Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.
Draw a card.

Myr Enforcer

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

Kenku Artificer

Homunculus Servant — When Kenku Artificer enters, put three +1/+1 counters on up to one target noncreature artifact. That artifact becomes a 0/0 Homunculus artifact creature with flying.

Frogmite

Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.