The Rock is a hand disruption and value midrange deck that relies on Duress and Cabal Therapy to strip your combo pieces, backed up by Pernicious Deed as a catch-all answer to any permanent-based setup. Their creatures — Ravenous Baloth, Spiritmonger, Stampeding Wildebeests — are irrelevant to your plan; what matters is navigating their discard before you can go off. Divert redirects Cabal Therapy or Duress back at them, potentially devastating their own hand and removing their main form of disruption for the turn. Blue Elemental Blast has no targets here but the slot it fills displaces Flash of Insight, which is too slow at 5 mana in this racing context; instead keep Divert as your primary protection. Recurring Nightmare in their deck can recover their threats post-Pernicious Deed but that's irrelevant to your game plan. Go off aggressively on turns 2-3 — their Haunting Echoes from the sideboard is a longer-game threat that removes your Ill-Gotten Gains and Cabal Ritual from the game entirely, so don't let the game go long.