Mono-Green Eldrazi is another big-mana ramp deck racing you to giant Eldrazi threats and Fight Rigging value, so the matchup comes down to who assembles their engine first and who can disrupt the other's key enablers. Grafdigger's Cage hurts their Green Sun's Zenith and Malevolent Rumble recursion loops similarly to the mirror-adjacent matchup. Nature's Claim is excellent against their Fight Rigging, a key enchantment enabling free-casting Ulamog or Emrakul. Disruptor Flute can name a problematic card like Fight Rigging or Green Sun's Zenith to tax it out of relevance. Unholy Heat is largely dead since their creatures (Slumbering Trudge 6/6, Fanatic of Rhonas 1/4, Emrakul 13/13) are almost all too tough even with delirium active, so it's better used as more targeted disruption.

This is the mirror, decided by who assembles their Basking Broodscale/Kozilek's Command engine faster and who protects it better. Grafdigger's Cage shuts off their Malevolent Rumble and Ancient Stirrings recursion plans while barely affecting your own gameplan, and Nature's Claim answers their Vexing Bauble or Blade of the Bloodchief cheaply. A second Vexing Bauble helps you counter their free spells like Kozilek's Command modes are not free so it mainly hits their own Vexing Bauble and any zero-cost interaction. Warping Wail's Eldrazi Scion mode and creature-exile mode both help you race their small Eldrazi. Unholy Heat is weak here since their key threats (Basking Broodscale, Devourer of Destiny) often have too much toughness once adapted, and Writhing Chrysalis is clunky against a deck that isn't attacking you with big creatures early.

Izzet Prowess wants to go fast and race through combat damage from Dragon's Rage Channeler, Monastery Swiftspear, and Slickshot Show-Off; you need cheap interaction that kills their small creatures before they snowball. The extra Unholy Heat is excellent since delirium is easy for you and 6 damage cleanly answers anything they play, while Warping Wail exiles their 1-toughness threats (Monastery Swiftspear, Dragon's Rage Channeler pre-delirium) or counters a key sorcery. Firespout as a one-sided-ish sweeper for 3 to non-flyers wipes their whole board when they overextend. Vexing Bauble comes out since most of their removal (Lightning Bolt, Lava Dart) and card draw (Preordain) is paid for with real mana, so it rarely counters anything; Writhing Chrysalis is too slow against a deck built to kill you before turn 5.