(: Add or to your mana pool.)
Tranquil Forge enters the battlefield tapped.
: Tranquil Forge becomes a 2/1 white and red Citizen creature until end of turn. It's still a land.
: Add 
or 
to your mana pool.): Tranquil Forge becomes a 2/1 white and red Citizen creature until end of turn. It's still a land.
