As Cavern of Souls enters the battlefield, choose a creature type.
: Add .
: 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.
: Add one mana of any color.
: Put a charge counter on Coalition Relic.
At the beginning of your precombat main phase, remove all charge counters from Coalition Relic. Add one mana of any color for each charge counter removed this way.
Cryptolith Fragment enters the battlefield tapped.
: Add one mana of any color. Each player loses 1 life.
At the beginning of your upkeep, if each player has 10 or less life, transform Cryptolith Fragment.
Converge — Crystalline Crawler enters the battlefield with a +1/+1 counter on it for each color of mana spent to cast it.
Remove a +1/+1 counter from Crystalline Crawler: Add one mana of any color.
: Put a +1/+1 counter on Crystalline Crawler.