Affinity's board is almost entirely artifacts, making Dust to Dust excellent: exiling two targets at once can take out key pieces like Baleful Strix, Myr Enforcer, or Cryogen Relic, or even hit an artifact land like Mistvault Bridge or Razortide Bridge to cripple their mana. Relic of Progenitus denies Blood Fountain recursion and can wipe their graveyard of discarded fuel if needed, though it doesn't interact with their board directly. Clowning Around's small tokens trade down badly into their efficient 2/1s, 3/3s, and the 4/4 Myr Enforcer, so cut it along with the lone Guardians' Pledge and a Novice Inspector to make room for artifact hate. Dispatch gets even better here since metalcraft is trivial for you, letting it exile their creatures outright instead of just tapping them.