Affinity is a fast artifact aggro deck that can present lethal with a pumped Kappa Cannoneer before you assemble Belcher, so you need to contest their board early with Suppression Ray and your counterspell suite while developing your combo. Post-board, Damping Sphere is the most dangerous hate piece — it prevents you from chaining spells in a single turn to generate the mana needed to cast and activate Charbelcher, so the additional Consign to Memory copies are your priority answer. Flusterstorm and Mystical Dispute come in to fight over their interaction, particularly their post-board Consign to Memory package and Metallic Rebuke. Stern Scolding and Into the Flood Maw come out because Affinity's relevant threats are too large for Scolding, and the tempo bounce of Flood Maw is too slow when you need to be either establishing a counter-backup or resolving Belcher. Keep your Force of Negation and Disrupting Shoal in to protect Whir of Invention and Goblin Charbelcher on the stack, as a countered Whir is often a game loss.