Affinity relies on cheap artifacts to enable Mox Opal, Urza's Saga constructs, and Kappa Cannoneer, and Brotherhood's End's second mode destroys all artifacts with mana value 3 or less, wiping out most of their board including Pinnacle Emissary and Weapons Manufacturing tokens. Mystical Dispute is live against their Metallic Rebuke and any blue spells, and even at full price it's efficient interaction against a deck trying to go wide fast. We cut Quantum Riddler since its 5-mana body is too slow and clunky against their explosive low curve, trim Wistfulness since its artifact/enchantment mode is redundant with Brotherhood's End and its body doesn't impact the race fast enough, and remove Dismember since Kappa Cannoneer's Ward 4 makes it a poor rate. Keep Force of Negation to stop Urza's Saga chapter III tutoring for a key artifact.