Oops, All Spells! is a turn-1 or turn-2 kill combo deck that wins by milling its own library with Balustrade Spy or Undercity Informer, triggering Narcomoeba from the graveyard, and flashing back Dread Return to reanimate Thassa's Oracle. Leyline of the Void is your best card in this matchup — with it in play, Narcomoeba gets exiled instead of triggering, collapsing the entire combo before Dread Return becomes live. Thoughtseize is already excellent pre-board; your goal is to resolve a Leyline in your opening hand or strip their key enablers before they go off on turn 1-2. Snuff Out gives you instant-speed interaction against Balustrade Spy or Undercity Informer — killing either in response to its activation prevents the self-mill entirely. Post-board they pivot to a Goblin Charbelcher plan with Lion's Eye Diamond, so Force of Vigor, a free instant that destroys artifacts and enchantments, handles that backup angle and should be held up or used proactively depending on the board state. Slow, incremental permanents like Elvish Reclaimer, Wight of the Reliquary, and Boseiju do nothing in a matchup decided in the first two turns, so trim them to make room for the hate.