Grixis Control plays almost entirely black and blue removal/counters with no red spells or permanents, so Pyroblast and Red Elemental Blast-style effects aren't in our sideboard, and nothing in our sideboard (Hydroblast only hits red, Dust to Dust only hits artifacts, Circle of Protection: Blue is symmetric life-saving but we're the blue deck too) meaningfully improves our position against their removal-heavy, countermagic-heavy build. Our best path is grinding with the existing Counterspell, Dispel, and card-advantage engine (Mulldrifter, Lorien Revealed, Archaeomancer looping Ephemerate value) to out-resource them in a long game. Keep the maindeck as configured since no sideboard swap clearly upgrades the 75 here.