Hey this is your classic Eldazi stompy deck modified to include and take advantage of Eternal Scourge, potentially creating card advantage while generating mana quickly.
Name of the deck is due to Cavern of Souls and Gemstone Caverns, and operating off of Eternal Scourge.
How to deal with the meta:
Grixis Delver: Bring in Warping Wail and Jitte, cutting 2 dismembers and 1 eternal scourge
Mirror Eldrazi: Bring in 2 jitte, coercive portal and a warping wail and cut 4 chalices
UR Delver: bring in 2x wastes (they usually play PoP or Blood Moon), cutting an urborg and gemstone cavern. Drop the dismembers for jitte since it tends to hurt quite a bit. thorn of amethyst may be useful as well.
UW Miracles: bring in 3 all is dust, coercive portal, and thorn of amethyst. cutting 2 dismembers (unless they are on mentor), 4 matter reshaper and 2 mimics.
Shardless Bug: bring in 3 all is dust and 2 jittes, cut 1 warping wail and 4 chalices. if you are playing leyline of the void in the sideboard (im still acquiring them) then also add those in and cut 3 simian spirit guides and 1 mimic.
Storm: bring in 2 thorns and 1 warping wail and cut 2 dismembers and 1 end bringer
Show and Tell: bring in 2 amethysts and 1 warping wail, 1 jitte and cut 4 chalices
Reanimator: bring in 4 faerie macabres/leyline of the void and cut 2 dismembers and 2 simian spirit guides
