UR Aggro is an all-red-and-blue tempo deck leaning on Slickshot Show-Off, Burst Lightning, and cheap cantrips, so Flashfreeze is a clean catch-all against their many red spells including Burst Lightning and Slickshot Show-Off. Requiting Hex cheaply answers Elusive Otter, Pompous Battlemage, or Slickshot Show-Off, all mana value 2 or less, while gaining life back against their aggressive clock. Trim Rapid Rescue and Awaken the Honored Dead for the extra interaction since this matchup rewards answering their cheap threats quickly over incidental card selection.