Spy Combo wins by assembling enough mana creatures to cast Balustrade Spy, milling the entire library and reanimating Lotleth Giant with Dread Return for a lethal trample attack. Your primary disruption is Duress, which can strip Dread Return or a key combo piece before they go off. Nihil Spellbomb is critical — it exiles the graveyard at instant speed, completely shutting off the Dread Return reanimation line mid-combo, so hold it until they start the chain. Tithing Blade is too slow and reactive against a deck that aims to win in one big turn, and Prismatic Strands doesn't protect against trample damage when Lotleth Giant will be enormous. Prioritize pressure with your artifact creature package and disruption; they have no meaningful interaction, so a fast clock backed by hand disruption and graveyard hate is often enough to win.