+"Land", +"Antiquities" (6)
: Add .
: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
: Target Assembly-Worker creature gets +1/+1 until end of turn.
: Add . Spend this mana only to cast artifact spells.
, Sacrifice Strip Mine: Destroy target land.
: Add . If you control an Urza's Power-Plant and an Urza's Tower, add instead.
: Add . If you control an Urza's Mine and an Urza's Tower, add instead.
: Add . If you control an Urza's Mine and an Urza's Power-Plant, add instead.
Gatherer works better in the Companion app!
: Add 
.
: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.: Target Assembly-Worker creature gets +1/+1 until end of turn.