Breath Weapon's 2 damage to each non-Dragon creature wipes Voldaren Epicure, Sneaky Snacker and Guttersnipe (leaving only the 1/3 Kessig Flamebreather), so it kills most of their mana-efficient payoffs at once. Weather the Storm buys life to survive the burn-to-the-face plan, and Relic of Progenitus can strip their graveyard to deny Lava Dart and Faithless Looting flashback value and slow Snacker's return (note it only exiles what's there, not madness cards discarded to exile). Cut the clunkier top-end (Sagu Wildling, Bannerhide Krushok) and Writhing Chrysalis, which are too slow against a deck trying to race you, in favor of cheap interaction and life gain. Keep the low curve creatures and mana dorks to pressure them before Fireblast becomes live.

Dimir Control has no red cards and almost no artifacts (only artifact creatures Baleful Strix and Mukotai Ambusher), so Vandalblast and the red hate stay home. Tamiyo's Safekeeping protects your key threats from Snuff Out, Cast Down and Agony Warp by giving hexproof and indestructible in response to removal, and gains incidental life against their grindy plan. Deglamer has few targets here, but it can shuffle a Baleful Strix (a flying deathtouch blocker) or Mukotai Ambusher back into their library. It won't stop the card Strix already drew on entering, so use it to clear a blocker or attacker rather than to deny value. Trim the slower Sagu Wildling and a couple Nyxborn Hydra copies, since they're clunky against cheap removal and counterspells; keep the low-cost beaters that punish their tapped-out turns.

Spy Combo relies on Balustrade Spy self-mill and Dread Return reanimation to build a graveyard-fueled board, so Relic of Progenitus lets you exile all graveyards (denying Dread Return targets and graveyard value, and shutting off a Dread Return flashback) while drawing a card. Remember that cracking it also exiles your own graveyard, so time it for when that costs you nothing. Breath Weapon's 2 damage to each non-Dragon creature kills their smallest mana creatures and utility bodies (Elves of Deep Shadow, Quirion Ranger, Gatecreeper Vine, Mesmeric Fiend), which slows their ramp. It does not kill Saruli Caretaker (0/3), Wall of Roots (0/5), or Overgrown Battlement (0/4), and it will also kill your own Arbor Elf, so don't count on it to clear their defenders. Trim slower top-end cards that don't interact with their combo pieces for this cheaper, more proactive disruption. Keep your sturdier cheap beaters like Jewel Thief, Eldrazi Repurposer, and Writhing Chrysalis, which survive Breath Weapon, to pressure them before they assemble their engine.