Great Furnace

Tundra

Underground Sea

Myr Galvanizer

Other Myr creatures you control get +1/+1.
{1}, {T}: Untap each other Myr you control.

Iron Myr

Savannah

Tree of Tales

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Swamp

Bayou

Alloy Myr

Scrubland

Darksteel Citadel

Seat of the Synod

Copper Myr

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Palladium Myr

Silver Myr

Vault of Whispers

Plateau

Plains

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Forest

Leaden Myr

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.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Badlands

Volcanic Island

Urtet, Remnant of Memnarch

Whenever you cast a Myr spell, create a 1/1 colorless Myr artifact creature token.
At the beginning of combat on your turn, untap each Myr you control.
{W}{U}{B}{R}{G}, {T}: Put three +1/+1 counters on each Myr you control. Activate only during your turn.