Throne of Geth

{T}, Sacrifice an artifact: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Myr Servitor

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

Urza's Power Plant

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

Treasure Vault

{T}: Add {C}.
{X}{X}, {T}, Sacrifice Treasure Vault: Create X Treasure tokens.

Tomb of the Spirit Dragon

{T}: Add {C}.
{2}, {T}: You gain 1 life for each colorless creature you control.

Mage-Ring Network

{T}: Add {C}.
{1}, {T}: Put a storage counter on Mage-Ring Network.
{T}, Remove any number of storage counters from Mage-Ring Network: Add {C} for each storage counter removed this way.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Sea Gate Wreckage

{T}: Add {C}. ({C} represents colorless mana.)
{2}{C}, {T}: Draw a card. Activate only if you have no cards in hand.

Urza's Mine

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

Phyrexia's Core

{T}: Add {C}.
{1}, {T}, Sacrifice an artifact: You gain 1 life.

Myr Sire

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

Expedition Map

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

Smokestack

At the beginning of your upkeep, you may put a soot counter on Smokestack.
At the beginning of each player's upkeep, that player sacrifices a permanent for each soot counter on Smokestack.

Myr Battlesphere

When Myr Battlesphere enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Urza's Tower

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

Tangle Wire

Fading 4 (This artifact enters with four fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
At the beginning of each player's upkeep, that player taps an untapped artifact, creature, or land they control for each fade counter on Tangle Wire.

Blast Zone

Blast Zone enters with a charge counter on it.
{T}: Add {C}.
{X}{X}, {T}: Put X charge counters on Blast Zone.
{3}, {T}, Sacrifice Blast Zone: Destroy each nonland permanent with mana value equal to the number of charge counters on Blast Zone.

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Buried Ruin: Return target artifact card from your graveyard to your hand.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Throne of the High City

{T}: Add {C}.
{4}, {T}, Sacrifice Throne of the High City: You become the monarch.