Eldrazi Tron's big colorless threats like Ulamog and Devourer of Destiny dodge Fatal Push entirely, so we trim it for the more flexible exile-based March of Otherworldly Light, which can answer a resolved Devourer of Destiny (at X=7), Sowing Mycospawn, or artifacts like Trinisphere and Talisman of Resilience. It can't touch Karn, the Great Creator or Ugin, Eye of the Storms, since planeswalkers aren't legal targets. Nihil Spellbomb is a low-impact include that can exile their graveyard, which blanks Abstergo Entertainment's recursion. Celestial Purge stays in the sideboard because Eldrazi Tron has no black or red permanents, so it would have no targets. Griselbrand is a weaker reanimation target than Atraxa here: as a black creature it can be exiled by Devourer of Destiny's cast trigger, and Atraxa's enter trigger gives us value immediately, which matters more than Griselbrand's draw ability in a long grindy game. Our best plan remains resolving the combo as fast as possible before they assemble Tron.