This is the mirror, so Trinisphere is excellent since both decks are built around cheap one- and two-mana spells like Ancient Stirrings and Malevolent Rumble, taxing the opponent's engine far more than your own Eldrazi top end. Thought-Knot Seer rips a key piece like Emrakul, the Promised End or a removal spell out of their hand while adding a solid clock. Pithing Needle can lock down a problematic Urza's Saga or a utility land. Cut the narrow one-mana artifacts and the mana rock that don't do enough in a grindy mirror where board presence and disruption matter more.

Izzet Prowess is a fast, low-curve aggro-tempo deck with no graveyard recursion, so Grafdigger's Cage mainly comes in as a cheap one-mana blocker-ignoring artifact body isn't relevant here, but Soul-Guide Lantern gives you an extra early artifact to slow nothing specific; prioritize it only as a marginal include if you need bodies. More importantly, the extra Dismember is premium removal against their small, efficient threats like Monastery Swiftspear and Dragon's Rage Channeler. Blade of the Bloodchief is too slow and low-impact against a deck that races, and the top-end Sire of Seven Deaths is too clunky versus their speed. Focus on surviving the early turns and stabilizing with Kozilek's Command and Dismember before your Eldrazi payoffs take over.

Nature's Claim is the cleanest answer to their Blade of the Bloodchief, destroying the equipment that powers the entire combo loop before it goes infinite. The extra Dismember gives you a cheap, instant-speed way to kill Basking Broodscale in response to the loop starting, which stops the whole engine since Blade's trigger needs Broodscale alive to make new Spawn tokens. Thought-Knot Seer strips a combo piece from their hand (Blade, Broodscale, or a key enabler) while also disrupting their plan proactively on the play. Cut your own copies of Blade of the Bloodchief since they're redundant in this fight, trim Devourer of Destiny as a clunky top-end card against a deck racing to go infinite, and cut Vexing Bauble/Haywire Mite as they're too slow or narrow compared to the proactive hate you're bringing in.