Missing sideboard cards? The full 15-card sideboard runs about $50.91.
Buy sideboard on ManapoolFade from History wipes their artifact and enchantment board (Urza's Saga, its Construct tokens, Blade of the Bloodchief, Vexing Bauble, Springleaf Drum, Talisman of Resilience). It is symmetrical, though: each player who controls an artifact or enchantment first creates a 2/2 Bear, and it also destroys our own Leyline of Abundance, Agatha's Soul Cauldron and Walking Ballista, so time it for when they have committed more to the board than we have. Our non-artifact creatures are untouched. Endurance is a flash, reach 3/4 body that puts a player's graveyard on the bottom of their library, which blanks Malevolent Rumble's graveyard filling and makes Emrakul, the Promised End cost more by removing card types from their graveyard. It can be evoked for free by exiling a green card from hand if we're tight on mana. Collector Ouphe shuts off activated abilities of artifacts, such as Blade of the Bloodchief's equip, Springleaf Drum, Talisman of Resilience, Soul-Guide Lantern and Haywire Mite's sacrifice ability. Urza's Saga is an Enchantment Land rather than an artifact, so its Construct-making chapter still works. Ouphe also turns off our own Walking Ballista and Agatha's Soul Cauldron abilities. We trim slow or situational pieces (Ouroboroid, Craterhoof, Fiend Artisan) and the -1/-1 counter synergy pieces (Vizier) that are less relevant against their grindy colorless shell.
Fade from History destroys their Blade of the Bloodchief, Urza's Saga and any Construct tokens it has made. Blade's counters are one way to trigger Basking Broodscale, so this cuts into their combo shell. Collector Ouphe stops activated abilities of artifacts, which shuts off Blade's equip ability, along with Springleaf Drum, Soul-Guide Lantern, Vexing Bauble and Haywire Mite. It does not stop Urza's Saga, because Saga is an Enchantment Land and not an artifact. Endurance can be evoked for no mana by exiling a green card from hand. Its enter trigger puts their graveyard on the bottom of their library, which undoes Ancient Stirrings and Malevolent Rumble setup and makes Emrakul, the Promised End much more expensive. We trim slow top-end and creatures that do little against their combo plan.
Fatal Push is premium cheap interaction against their sub-2-mana creatures (Dragon's Rage Channeler, Monastery Swiftspear, Slickshot Show-Off), snapping them off before they get going with prowess triggers. Endurance is a free (evoke) flash blocker with Reach that survives most of their burn and gums up the ground. We cut top-end and slower value pieces that are too clunky against a fast aggressive deck that wants to race us before we assemble our engine. Keep the full mana engine intact since we need to come online quickly to out-value their burn.