Darksteel Citadel

Great Furnace

{1}, {T}, Sacrifice Chromatic Sphere: Add one mana of any color. Draw a card.

{1}, {T}, Sacrifice Chromatic Star: Add one mana of any color.
When Chromatic Star is put into a graveyard from the battlefield, draw a card.

{T}, Sacrifice Conjurer's Bauble: Put up to one target card from your graveyard on the bottom of your library. Draw a card.

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

Whenever an artifact is put into a graveyard from the battlefield, you may have target opponent lose 1 life.

Artifact spells you cast cost {1} less to cast.

Flying
Whenever you cast an artifact spell, you may untap target creature.

Battered Golem doesn't untap during your untap step.
Whenever an artifact enters, you may untap Battered Golem.

Enchant creature
Enchanted creature has "{T}: This creature deals 1 damage to target player or planeswalker. You draw a card."

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

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

{R}, Sacrifice Pyrite Spellbomb: It deals 2 damage to any target.
{1}, Sacrifice Pyrite Spellbomb: Draw a card.

{T}: Target player exiles a card from their graveyard.
{1}, Exile Relic of Progenitus: Exile all graveyards. Draw a card.

Sacrifice Bottle Gnomes: You gain 3 life.