Amulet Titan relies on Amulet of Vigor, Urza's Saga, Spelunking, and bounce lands to generate explosive mana, so the extra two copies of Nature's Claim destroy these key artifacts and enchantments (Amulet of Vigor, Spelunking, and the enchantment land Urza's Saga) before they take over the game. Into the Flood Maw is a cheap tempo play: it can bounce a creature, or with the gift, a nonland permanent such as Amulet of Vigor or Spelunking, costing them mana and a turn. We have no clean answer to Primeval Titan or a large Cultivator Colossus in the sideboard, so Dismember stays out. At -5/-5 it leaves a 6/6 Titan alive and Colossus is usually far too big. We trim a Disciple of Freyalise and Hooting Mandrills, which are clunky value creatures that don't pressure a combo deck fast enough, and Xenagos, since this matchup is a race against their assembly rather than a combat-damage plan. The core Allosaurus Rider into Eldritch Evolution/Neoform game plan stays fully intact to race them to Griselbrand or Atraxa before Scapeshift or Primeval Titan chains take over.