Cavern of Souls (0410b) (Borderless) [The Lost Caverns of Ixalan]

Set: The Lost Caverns of Ixalan Type: Land Rarity: Mythic As Cavern of Souls enters the battlefield, choose a creature type.{T}: Add {C}.{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.