When Smoldering Key enters the battlefield, sacrifice it unless you pay .
, : Add to your mana pool.
: Smoldering Key becomes a 1/1 blue and red Troll creature with flying until end of turn. It's still a land.
.
, 
: Add to your mana pool., : Add to your mana pool.
: Smoldering Key becomes a 1/1 blue and red Troll creature with flying until end of turn. It's still a land.
