This is a pure speed race: they go over the top with Show and Tell into Atraxa, Grand Unifier or Omniscience, so our single-draw-step discard spells are too slow and risk running into Veil of Summer, which punishes black spells by making them hexproof from black. Feed the Swarm can answer a resolved Atraxa, Grand Unifier or Acererak the Archlich before it generates too much value, while Surgical Extraction can strip a key piece like Aluren or a copy of Show and Tell out of their deck/graveyard after it's been used once. We're cutting discard spells rather than any combo pieces since our plan is still to go under them and win first.