Collector Ouphe is strong here, shutting off the activated abilities of their artifacts, including Mox Opal, Lotus Petal, Chrome Mox, Seat of the Synod, the Baubles and Tormod's Crypt, which cripples much of their mana development. It also shuts off our own Mox Diamond, so sequence around that. Prismatic Ending can exile key mana value 0-1 permanents like Mox Opal, Lotus Petal, or a Construct token. We cut slower, situational cards since this matchup is a race to disrupt their engine before Kappa Cannoneer or Emry take over; Wasteland remains critical against Urza's Saga and Seat of the Synod.