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.