Affinity relies heavily on artifacts for mana (Mox Opal), card selection (Mishra's Bauble), sweeping our board (Engineered Explosives), and win conditions (Kappa Cannoneer, Pinnacle Emissary), so Force of Vigor can blow up two of their key artifacts or enchantments at instant speed, ideally for free by exiling a green card on their turn. Collector Ouphe shuts off the activated abilities of their artifacts, including Mox Opal, Engineered Explosives, Mishra's Bauble, Tormod's Crypt, Welding Jar, Claws of Gix, and Shadowspear. This cripples their mana and game plan. It does nothing to Urza's Saga, which is an enchantment land rather than an artifact, so we still need to deal with that separately. Summoner's Pact is too slow and risky since Affinity can counter it with Metallic Rebuke unless we pay {3}, or race us before we can pay for it at our next upkeep, so it comes out along with the clunky Aftermath Analyst. This is a racing matchup where disrupting their engine while deploying Primeval Titan quickly is the priority.