Eldrazi relies heavily on Ancient Tomb and Eldrazi Temple to ramp into Chalice of the Void and big colorless threats like Reality Smasher and Thought-Knot Seer, so Damping Sphere caps how much mana those lands produce and taxes their clustered spell casting on key turns. The extra Toxic Deluge gives us a sweeper against their 2/2-4/4 creature suite since paying enough life clears Thought-Knot Seer, Glaring Fleshraker, and Eldrazi Linebreaker. Unlicensed Hearse helps remove their Eldrazi Spawn-generating creatures' graveyard value and grows into a blocker. Drown in the Loch and Stock Up are cut since their graveyards stay nearly empty, making Drown's mode weak, while Force of Negation and one Snuff Out are trimmed since they tend to be uncontested on noncreature spells but Chalice of the Void can still shut off our one-ofs, so keeping some flexibility matters more than overloading on narrow answers.