Fall from Favor

Enchant creature
When Fall from Favor enters, tap enchanted creature and you become the monarch.
Enchanted creature doesn't untap during its controller's untap step unless that player is the monarch.

Springleaf Drum

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

Galvanic Blast

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

Frogmite

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

Darksteel Citadel

Thriving Bluff

Thriving Bluff enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Thoughtcast

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

Atog

Sacrifice an artifact: Atog gets +2/+2 until end of turn.

Kor Skyfisher

Flying
When Kor Skyfisher enters, return a permanent you control to its owner's hand.

Plains

Ardent Recruit

Metalcraft — Ardent Recruit gets +2/+2 as long as you control three or more artifacts.

Prophetic Prism

When Prophetic Prism enters, draw a card.
{1}, {T}: Add one mana of any color.

Ancient Den

Myr Enforcer

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.

Thraben Inspector

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

Chromatic Star

{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.