Spy Combo's entire kill routes through Dread Return reanimating a fatty (often after self-milling with Balustrade Spy) or through Lotleth Giant's undergrowth trigger, both of which require a stocked graveyard, so Faerie Macabre is premium disruption — discard it to exile up to two target cards from their graveyard to strip Dread Return or its reanimation targets and reduce Lotleth Giant's damage trigger. Duress strips Dread Return itself or another key noncreature piece like Winding Way before they can chain into their combo. This is a pure race between two combo decks, so prioritize disrupting their graveyard over racing creature damage. Trim your slowest, least relevant bodies for the extra interaction.