Ingenious Artillerist

Whenever one or more artifacts you control enter, this creature deals that much damage to each opponent.

Skyclave Apparition

When this creature enters, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less.
When this creature leaves the battlefield, the exiled card's owner creates an X/X blue Illusion creature token, where X is the mana value of the exiled card.

Pre-War Formalwear

When this Equipment enters, return target creature card with mana value 3 or less from your graveyard to the battlefield and attach this Equipment to it.
Equipped creature gets +2/+2 and has vigilance.
Equip {3}

Hourglass of the Lost

{T}: Add {W}. Put a time counter on this artifact.
{T}, Remove X time counters from this artifact and exile it: Return each nonland permanent card with mana value X from your graveyard to the battlefield. Activate only as a sorcery.

Containment Construct

Whenever you discard a card, you may exile that card from your graveyard. If you do, you may play that card this turn.

Myr Retriever

When this creature dies, return another target artifact card from your graveyard to your hand.

Cursed Mirror

{T}: Add {R}.
As this artifact enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

The Core

(Transforms from Matzalantli.)
Fathomless descent — {T}: Add X mana of any one color, where X is the number of permanent cards in your graveyard.

Matzalantli, the Great Door

{T}: Draw a card, then discard a card.
{4}, {T}: Transform Matzalantli. Activate only if there are four or more permanent types among cards in your graveyard. (Artifact, battle, creature, enchantment, land, and planeswalker are permanent types.)

Matzalantli, the Great Door // The Core

Mishra, Excavation Prodigy

Haste
{1}, {T}, Discard a card: Draw a card.
Whenever you discard one or more artifact cards, add {R}{R}. This ability triggers only once each turn.

Myr Welder

Imprint — {T}: Exile target artifact card from a graveyard.
This creature has all activated abilities of all cards exiled with it.

Currency Converter

Whenever you discard a card, you may exile that card from your graveyard.
{2}, {T}: Draw a card, then discard a card.
{T}: Put a card exiled with this artifact into its owner's graveyard. If it's a land card, create a Treasure token. If it's a nonland card, create a 2/2 black Rogue creature token.

Portable Hole

When this artifact enters, exile target nonland permanent an opponent controls with mana value 2 or less until this artifact leaves the battlefield.

Dualcaster Mage

Flash
When this creature enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Village Bell-Ringer

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, untap all creatures you control.

Wake the Past

Return all artifact cards from your graveyard to the battlefield. They gain haste until end of turn.

Fabrication Foundry

{T}: Add {W}. Spend this mana only to cast an artifact spell or activate an ability of an artifact source.
{2}{W}, {T}, Exile one or more other artifacts you control with total mana value X: Return target artifact card with mana value X or less from your graveyard to the battlefield. Activate only as a sorcery.

Sevinne's Reclamation

Return target permanent card with mana value 3 or less from your graveyard to the battlefield. If this spell was cast from a graveyard, you may copy this spell and may choose a new target for the copy.
Flashback {4}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Surly Badgersaur

Whenever you discard a creature card, put a +1/+1 counter on this creature.
Whenever you discard a land card, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever you discard a noncreature, nonland card, this creature fights up to one target creature you don't control.

Imperial Recruiter

When this creature enters, search your library for a creature card with power 2 or less, reveal it, put it into your hand, then shuffle.

Battlemage's Bracers

Equipped creature has haste.
Whenever an ability of equipped creature is activated, if it isn't a mana ability, you may pay {1}. If you do, copy that ability. You may choose new targets for the copy.
Equip {2}

Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Junk Diver

Flying
When this creature dies, return another target artifact card from your graveyard to your hand.

Blasting Station

{T}, Sacrifice a creature: This artifact deals 1 damage to any target.
Whenever a creature enters, you may untap this artifact.

Zirda, the Dawnwaker

Companion — Each permanent card in your starting deck has an activated ability. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Abilities you activate that aren't mana abilities cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{1}, {T}: Target creature can't block this turn.

Recommission

Return target artifact or creature card with mana value 3 or less from your graveyard to the battlefield. If a creature enters this way, it enters with an additional +1/+1 counter on it.

Dusk Rose Reliquary

As an additional cost to cast this spell, sacrifice an artifact or creature.
Ward {2}
When this artifact enters, exile target artifact or creature an opponent controls until this artifact leaves the battlefield.

Selfless Spirit

Flying
Sacrifice this creature: Creatures you control gain indestructible until end of turn.