Hydroblast cheaply counters or destroys Fiery Temper, Lightning Bolt, Guttersnipe, and Kessig Flamebreather, all red. Dispel counters a key instant like Fiery Temper or Lava Dart, or protects our own spell from instant-speed interaction. Graveyard hate is irrelevant since madness cards are discarded into exile, not the graveyard, so we skip it. Cut the slower Essence Flux and stun-counter Snaremaster Sprite/Harrier Strix for direct interaction, since cheap answers matter more than incremental value in this race.

Dispel answers their instants, so it protects our Counterspell and Spellstutter Sprite from their Counterspell or Dispel, and it protects a Ninja of the Deep Hours already on the battlefield from Snuff Out or Cast Down. Steel Sabotage is narrow but live, able to counter or bounce Baleful Strix or Mukotai Ambusher and deny their value. Hydroblast has no legal targets since Dimir Control has no red cards, so it stays in the sideboard. Trim Essence Flux and Snaremaster Sprite for more direct interaction, since protecting our threats matters more than incremental value against this grindy control deck.

Unable to Scream permanently neutralizes their biggest threats, like Troll of Khazad-dum, Generous Ent, or Sagu Wildling, stripping abilities and shrinking them to a vanilla 0/2. Envelop counters key sorceries like Lead the Stampede, Winding Way, or Dread Return, cutting off their card advantage and reanimation plan. Keep Counterspell and Snap for Balustrade Spy and other threats. Trim the slower Essence Flux, Harrier Strix, and Saiba Cryptomancer since we want to be proactive against their go-wide, ramp-based plan.