Ancient Den

Electrickery

Electrickery deals 1 damage to target creature you don't control.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Frogmite

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

Armadillo Cloak

Enchant creature
Enchanted creature gets +2/+2 and has trample.
Whenever enchanted creature deals damage, you gain that much life.

Circle of Protection: Green

{1}: The next time a green source of your choice would deal damage to you this turn, prevent that damage.

Chromatic Sphere

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

Tree of Tales

Circle of Protection: Red

{1}: The next time a red source of your choice would deal damage to you this turn, prevent that damage.

Perilous Research

Draw two cards, then sacrifice a permanent.

Ichor Wellspring

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

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.

Chromatic Star

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

Myr Enforcer

Galvanic Blast

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

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Great Furnace

Vault of Whispers

Seat of the Synod

Springleaf Drum

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

Atog

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

Dispel

Thoughtcast

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

Reaping the Graves

Return target creature card from your graveyard to your hand.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Carapace Forger

Metalcraft — This creature gets +2/+2 as long as you control three or more artifacts.

Ancient Grudge

Destroy target artifact.
Flashback {G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)