MAGIC: THE GATHERING
As Cavern of Souls enters the battlefield, choose a creature type.
: Add to your mana pool.
: Add one mana of any color to your mana pool. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.
This powerful land allows tribal decks to fix their mana and crush counterspell decks. It is a mainstay of everything from Elves to Eldrazi, and Goblins to Slivers.