Urza's Mine

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

Urza's Tower

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

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

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

Until end of turn, if damage would be dealt to any creature, you may have that damage dealt to you instead.

Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)
Protection from white