Consign to Memory is a strong counter here because Affinity relies on colorless artifacts like Engineered Explosives, Mox Opal and Shadowspear, plus triggered abilities such as Weapons Manufacturing's Munitions creation. Its replicate mode lets us answer multiple triggered abilities in one spell. It can't counter Kappa Cannoneer or Pinnacle Emissary themselves, since both are colored spells. Mystical Dispute covers those: it counters their blue spells like Kappa Cannoneer, Pinnacle Emissary, Metallic Rebuke or Sink into Stupor cheaply. Ephemerate loses value since Affinity has little in the way of our own ETB creatures worth blinking in a must-answer-their-board race, and Thraben Charm's damage mode is weak against their resilient artifact creatures, especially Kappa Cannoneer with ward {4}.