This Gruul deck relies on Urza's Saga, Eldrazi Temple, and Ugin's Labyrinth for value and ramp, so Meltdown at X=0 or X=1 cleanly answers Urza's Saga's Construct tokens and other cheap artifacts before they take over. Nihil Spellbomb and Surgical Extraction disrupt Malevolent Rumble's graveyard fill and can strip away cards it puts into the graveyard, plus Nihil Spellbomb replaces itself. Lightning Bolt actually kills their small creatures like Basking Broodscale and Glaring Fleshraker just fine, but it's a weak answer to their bigger threats like Emrakul, so trim it for artifact and graveyard hate; Cling to Dust is similarly low-impact against their bigger threats.

Izzet Prowess is a fast noncreature-spell deck, so Consign to Memory is excellent, countering colorless spells like Mishra's Bauble and stopping triggered abilities like Cori-Steel Cutter's Flurry. Fire Magic's Fira mode (3 mana, 2 damage) wipes Monastery Swiftspear and Slickshot Show-Off cheaply, though it won't kill a delirium Dragon's Rage Channeler once it's a 3/3. Sheoldred's Edict is weak here since it only hits one creature per cast against a go-wide aggro plan, so trim it for cheaper interaction; Cryptic Command is clunky at 4 mana against a deck that kills fast. Surgical Extraction can strip a key Lightning Bolt or Expressive Iteration after it resolves once, denying redundancy.

Esper Blink leans on flicker triggers (Flickerwisp, Phelia) which are noncreature/nonspell triggered abilities that Consign to Memory can counter, disrupting their value engine before it resolves. Note it can't touch Ephemerate itself, since that's a white instant spell rather than a triggered ability or colorless spell. Mystical Dispute gets its full discount against their blue spells like Quantum Riddler and can also just tax anything else for 3. Lightning Bolt is weak against their evasive or protected threats (Overlord of the Balemurk, Solitude) and doesn't answer enchantments/planeswalkers like Teferi, Time Raveler, so trim it; Sheoldred's Edict is fine but slightly less needed with only a handful of true creature threats to force sacrifices on.