Cursed Totem shuts off Basking Broodscale's adapt activation and the sacrifice-for-mana ability on their Eldrazi Spawn tokens (and Haywire Mite's sacrifice ability), which is huge against their ramp-creature plan. Damping Sphere slows down Eldrazi Temple and Ugin's Labyrinth mana acceleration, buying time against their big-mana top end. Galvanic Blast is clean, cheap removal for their small creatures and can go face if needed. Salvage Titan and Claws of Gix are too slow against a deck that can out-grind with Emrakul and Kozilek's Command; Skateboard is low impact here. Keep Engineered Explosives in to blow up their Eldrazi Spawn tokens and small permanents at low mana values.

Cursed Totem is the single best sideboard card here: Basking Broodscale's adapt and the Eldrazi Spawn sacrifice ability are both activated abilities of creatures, so Totem shuts them off. Those are the pieces the Blade of the Bloodchief loop relies on, so it becomes very hard for them to get the loop going while Totem is in play. Metallic Rebuke is cheap, efficient interaction that counters a spell unless its controller pays {3}, so it can hit Blade of the Bloodchief, Basking Broodscale, or another key creature they try to resolve. It can't touch Urza's Saga, which is a land, or any activated ability. Improvise lets us pay for it with our artifacts, which makes it easier to hold up alongside our own development. Salvage Titan and Claws of Gix are too slow and don't interact with the combo, so they come out. Keep Engineered Explosives in the mainboard as an answer to Blade of the Bloodchief and Eldrazi Spawn tokens at low mana values.

Consign to Memory counters their colorless spells (Mishra's Bauble) and any triggered abilities, such as prowess, Dragon's Rage Channeler's surveil, Slickshot Show-Off's pump, and Cori-Steel Cutter's flurry trigger. That matters against a deck full of cheap noncreature-spell triggers. Cori-Steel Cutter itself is a red spell, so Consign can't counter it as a spell. Galvanic Blast cheaply answers Dragon's Rage Channeler, Monastery Swiftspear, and Slickshot Show-Off before they get out of hand, with Metalcraft upside to kill bigger threats. Whipflare sweeps most of their low-toughness creatures (Swiftspear, Slickshot, and Monk tokens are 1-2 toughness, and Dragon's Rage Channeler is 1/1 until delirium) for two mana, while our artifact creatures survive. Salvage Titan and Claws of Gix are too slow against this aggressive tempo deck, and Pithing Needle and Skateboard have weak targets here.