Urza's Mine

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

Mountain

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Flying
Whenever you cast an artifact spell, you may untap target creature.

Whenever another creature enters, you gain 1 life.

Whenever you cast a creature spell, Furious Assault deals 1 damage to target player or planeswalker.

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

Devoid (This card has no color.)
{T}: Nettle Drone deals 1 damage to each opponent.
Whenever you cast a colorless spell, untap Nettle Drone.

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

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

Until end of turn, target creature gains "{T}: Return target nonland permanent to its owner's hand."