Ancient Den

Glint Hawk

Flying
When Glint Hawk enters the battlefield, sacrifice it unless you return an artifact you control to its owner's hand.

Thraben Inspector

When Thraben Inspector enters the battlefield, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Seat of the Synod

Gearseeker Serpent

This spell costs {1} less to cast for each artifact you control.
{5}{U}: Gearseeker Serpent can't be blocked this turn.

Great Furnace

Galvanic Blast

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

Voldaren Epicure

When Voldaren Epicure enters the battlefield, it deals 1 damage to each opponent. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Springleaf Drum

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

Lembas

When Lembas enters the battlefield, scry 1, then draw a card.
{2}, {T}, Sacrifice Lembas: You gain 3 life.
When Lembas is put into a graveyard from the battlefield, its owner shuffles it into their library.

Razortide Bridge

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

Myr Enforcer

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

Rustvale Bridge

Rustvale Bridge enters the battlefield tapped.
Indestructible
{T}: Add {R} or {W}.

Thoughtcast

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

Reckless Fireweaver

Whenever an artifact enters the battlefield under your control, Reckless Fireweaver deals 1 damage to each opponent.

Makeshift Munitions

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

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Wedding Invitation

When Wedding Invitation enters the battlefield, draw a card.
{T}, Sacrifice Wedding Invitation: Target creature can't be blocked this turn. If it's a Vampire, it also gains lifelink until end of turn.

Kuldotha Rebirth

As an additional cost to cast this spell, sacrifice an artifact.
Create three 1/1 red Goblin creature tokens.

All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Frogmite

Silverbluff Bridge

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Experimental Synthesizer

When Experimental Synthesizer enters or leaves the battlefield, exile the top card of your library. Until end of turn, you may play that card.
{2}{R}, Sacrifice Experimental Synthesizer: Create a 2/2 white Samurai creature token with vigilance. Activate only as a sorcery.