Iron Myr

Power Plant Worker

{3}: This creature gets +2/+2 until end of turn. If you control creatures named Mine Worker and Tower Worker, put two +1/+1 counters on this creature instead. Activate only once each turn.

Urza's Tower

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

Ashnod's Altar

Tower Worker

Reach
{T}: Add {C}. If you control creatures named Mine Worker and Power Plant Worker, add {C}{C}{C} instead.

Mine Worker

{T}: You gain 1 life. If you control creatures named Power Plant Worker and Tower Worker, you gain 3 life instead.

Mountain

Disintegrate

Disintegrate deals X damage to any target. If it's a creature, it can't be regenerated this turn, and if it would die this turn, exile it instead.

Golem Foundry

Whenever you cast an artifact spell, you may put a charge counter on this artifact.
Remove three charge counters from this artifact: Create a 3/3 colorless Golem artifact creature token.

Myr Retriever

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

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Pirate's Pillage

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Urza's Mine

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

Oxidda Golem

Affinity for Mountains (This spell costs {1} less to cast for each Mountain you control.)
Haste

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Urza's Power Plant

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