Urza's Tower

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

Mox Emerald

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

{T}: Add {C}.
{T}, Sacrifice this land: Destroy target land.

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

When this creature dies, add {C}{C}{C}{C}.

{T}: Add {C}.
{T}: Draw a card. Activate only if you have exactly seven cards in hand.

{1}, {T}: Tap target artifact, creature, or land.

This creature attacks each combat if able.
This creature can't be blocked by Walls.

{T}, Sacrifice this artifact: Add three mana of any one color.

{T}: Add {C}{C}{C}. Spend this mana only to cast artifact spells.