Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Sparring Construct

When this creature dies, put a +1/+1 counter on target creature you control.

Vault of Whispers

Skyscanner

Flying
When this creature enters, draw a card.

Seat of the Synod

Darksteel Citadel

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Ancient Den

Glimmerpost

When this land enters, you gain 1 life for each Locus on the battlefield.
{T}: Add {C}.

Sunscorched Desert

When this land enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Myr Enforcer

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

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Excavated Wall

Defender
{1}, {T}: Mill a card. (Put the top card of your library into your graveyard.)

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)
This creature attacks each combat if able.

Great Furnace

Myr Retriever

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

Myr Sire

When this creature dies, create a 1/1 colorless Phyrexian Myr artifact creature token.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Perilous Myr

When this creature dies, it deals 2 damage to any target.

Tree of Tales

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Automated Artificer

{T}: Add {C}. Spend this mana only to activate an ability or cast an artifact spell.

Eldrazi Devastator

Myr Scrapling

Sacrifice this creature: Put a +1/+1 counter on target creature.

Haunted Fengraf

{T}: Add {C}.
{3}, {T}, Sacrifice this land: Return a creature card at random from your graveyard to your hand.

Rusted Relic

Metalcraft — This artifact is a 5/5 Golem artifact creature as long as you control three or more artifacts.

Expanded Anatomy

Put two +1/+1 counters on target creature. It gains vigilance until end of turn.

Heap Gate

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{1}, {T}, Tap an untapped Gate you control: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Frogmite

Alchemist's Vial

When this artifact enters, draw a card.
{1}, {T}, Sacrifice this artifact: Target creature can't attack or block this turn.

Myr Servitor

At the beginning of your upkeep, if this creature is on the battlefield, each player returns all cards named Myr Servitor from their graveyard to the battlefield.

Peace Strider

When this creature enters, you gain 3 life.

Stonework Packbeast

Stonework Packbeast is also a Cleric, Rogue, Warrior, and Wizard.
{2}: Add one mana of any color.

Myr Kinsmith

When this creature enters, you may search your library for a Myr card, reveal it, put it into your hand, then shuffle.

Cogwork Archivist

Reach
{2}, {T}: Put target card from a graveyard on the bottom of its owner's library.