Drossforge Bridge

This land enters tapped.
Indestructible
{T}: Add {B} or {R}.

Frogmyr Enforcer

Prototype {3}{R} — 2/2 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Sunbeam Spellbomb

{W}, Sacrifice this artifact: You gain 5 life.
{1}, Sacrifice this artifact: Draw a card.

Ichor Wellspring

When this artifact enters or is put into a graveyard from the battlefield, draw a card.

Darkmoss Bridge

This land enters tapped.
Indestructible
{T}: Add {B} or {G}.

Swamp

Forest

Twisted Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle.
Cycling {B}{R}{G} ({B}{R}{G}, Discard this card: Draw a card.)

Myr Enforcer

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

Mountain

Vault of Whispers

Lifespark Spellbomb

{G}, Sacrifice this artifact: Until end of turn, target land becomes a 3/3 creature that's still a land.
{1}, Sacrifice this artifact: Draw a card.

Makeshift Munitions

{1}, Sacrifice an artifact or creature: This enchantment deals 1 damage to any target.

Frogmite

Refurbished Familiar

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When this creature enters, each opponent discards a card. For each opponent who can't, you draw a card.

Slagwoods Bridge

This land enters tapped.
Indestructible
{T}: Add {R} or {G}.

Scene of the Crime

This land enters tapped.
{T}: Add {C}.
{T}, Tap an untapped creature you control: Add one mana of any color.
{2}, Sacrifice this land: Draw a card.

Tree of Tales

Darksteel Citadel

Nihil Spellbomb

{T}, Sacrifice this artifact: Exile target player's graveyard.
When this artifact is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

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.

Horizon Spellbomb

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
When this artifact is put into a graveyard from the battlefield, you may pay {G}. If you do, draw a card.

Great Furnace

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)