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.

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.

Esper GenericBlink relies heavily on nonbasic lands and blink value creatures like Phelia and Flickerwisp, so Harbinger of the Seas turning their nonbasics into Islands can strand their white/black mana for Solitude, Overlord of the Balemurk, and Ephemerate. Engineered Explosives sweeps their cheap value creatures (Phelia, Emperor of Bones, Orcish Bowmasters) at low charge counters, and Mystical Dispute is live since they run blue spells like Kaito and Teferi, Time Raveler. Spell Snare loses some targets since their curve includes 1-drops, Solitude evokes, and higher-cost threats alongside 2-drops like Phelia, so trim it along with Sink into Stupor which is weak against their resilient blink engine; cut one Preordain for interaction. Keep Thoughtseize and Fatal Push as premium disruption against their key blink pieces and removal.