When Rustic Cairns enters the battlefield, sacrifice it unless you pay .
, : Add to your mana pool.
: Rustic Cairns becomes a 0/4 white and black Bird creature with defender until end of turn. It's still a land.
.
, 
: Add to your mana pool., : Add to your mana pool.
: Rustic Cairns becomes a 0/4 white and black Bird creature with defender until end of turn. It's still a land.
