Mono Red Rally wants to dump its board with Burning-Tree Emissary and Voldaren Epicure, then swing for lethal off Rally at the Hornburg or a kicked Goblin Bushwhacker, so Darkness is your best card in the whole sideboard here — it prevents all combat damage the turn they try to alpha strike, buying a full extra turn to assemble Songs of the Damned. Weather the Storm's storm count grows naturally off our ritual-heavy turns and the lifegain matters against a deck racing for exact lethal. Faerie Macabre comes in as a flying blocker that can chump the token wave while also discarding itself for value if needed, though note it won't stop anything meaningful since Rally's tokens aren't graveyard-dependent. We trim our slowest, clunkiest cards — Repository Skaab, Horror of the Broken Lands, and the Architects of Will — since this matchup is decided by surviving to combo off, not grinding card advantage.