This is a near-mirror where both decks race to resolve Show and Tell (and, for them, Aluren) into Atraxa and Omniscience. Consign to Memory costs only {U}, so it is cheap interaction that can counter a triggered ability, such as their Atraxa or Acererak triggers, or a colorless spell like Lotus Petal. That matters when both sides are tight on resources. Spell Pierce is a worse fit here since they can protect their key spells with Force of Will, and their Veil of Summer can blank countermagic aimed at their spells anyway. Keep all core engine pieces (Show and Tell, Sneak Attack, Omniscience) untouched since this matchup is decided by who assembles their combo first and who disrupts the other's lands and petals.