Affinity is an artifact mirror-adjacent matchup, and Dust to Dust is the best card in your deck here. It's a sorcery that exiles two target artifacts, and their deck is full of them: Utrom Monitor, Baleful Strix, Refurbished Familiar, Cryogen Relic, Giant's Boulder, and their artifact lands all make good targets. Kor Skyfisher and Glint Hawk are plain white creatures, so Dust to Dust can't touch them. The extra Thraben Charm copies scale off your wide board of small creatures and can kill Baleful Strix or another small creature, while also offering a graveyard-exile mode against their Blood Fountain recursion. Cut the narrow or slow cards: Omen of the Dead and Eviscerator's Insight don't affect their board quickly enough, Nihil Spellbomb is a low-impact card here that does nothing to pressure their board, and Thorn of the Black Rose's monarch is hard to hold against their evasive fliers. Keep your own artifact lands and Refurbished Familiars since they're just as good on both sides of this mirror-like matchup.