Mono-Green Eldrazi ramps through colorless lands and mana dorks into giant threats like Emrakul, the Promised End, Ulamog, and Ugin, so Toxic Deluge sweeps their creatures (Fanatic of Rhonas, Sowing Mycospawn, Disciple of Freyalise) while Engineered Explosives answers Fanatic of Rhonas and early tokens before they hit their ramp targets. Nihil Spellbomb disrupts their graveyard to prevent Malevolent Rumble from reducing the cost of Emrakul, the Promised End. Force of Negation and Spell Snare are weaker here since their key threats are colorless and mostly uncounterable by cost-restricted spells or land-heavy draws that dodge countermagic timing windows; trim both for proactive removal. Keep Fatal Push and Sheoldred's Edict live against their dorks and use Thoughtseize to strip their ramp pieces before they can assemble a fast Emrakul or Ulamog.

Izzet Prowess is an aggressive tempo deck full of cheap noncreature spells and hasty threats like Slickshot Show-Off and Cori-Steel Cutter tokens, so Consign to Memory's replicate ability lets you counter multiple colorless spells or triggered abilities in one turn, hitting things like Mishra's Bauble and Cori-Steel Cutter's Flurry trigger. Harbinger of the Seas turns their nonbasic lands into Islands, straining their red mana for Lightning Bolt and Lava Dart. Force of Negation is too reactive and narrow against a deck that wins through incremental damage rather than one big spell, and Spell Snare has fewer relevant 2-mana targets, so trim both for more efficient interaction. Keep Fatal Push, Orcish Bowmasters, and Psychic Frog as your primary tools to trade with their small creatures and stabilize.

This Gruul deck wants to ramp through Ancient Stirrings and colorless lands into Emrakul, the Promised End or Devourer of Destiny, so graveyard hate from Nihil Spellbomb and Ghost Vacuum slows their Malevolent Rumble and Kozilek's Command loops while denying value. Engineered Explosives and Toxic Deluge answer their creature-based ramp (Basking Broodscale, Glaring Fleshraker, Eldrazi Spawn tokens) before they hit critical mass, and countermagic is less impactful since much of their plan is colorless creatures and lands that dodge Spell Snare and generic counters poorly interact with mana abilities. Trim Force of Negation and some Counterspell/Spell Snare copies for proactive removal and sweepers, keeping Fatal Push and Sheoldred's Edict live against their key threats. Race efficiently with Psychic Frog and Murktide Regent while disrupting their ramp engine.