Omni-Tell is a mirror-adjacent matchup that also wants to resolve Show and Tell into Omniscience or Atraxa, Grand Unifier, so the game is a race to disrupt their combo turn while protecting your own; Force of Negation lets you counter their Show and Tell for free on their turn since it's noncreature, which is often the single best interaction available. Consign to Memory hits Lotus Petal-fueled colorless spells and any triggered abilities they generate, giving you cheap, efficient interaction to disrupt their setup. Since both players run similar plans, redundant copies of Omniscience are less valuable than interaction that stops the opponent from resolving theirs first, so trim to one copy; Veil of Summer is also cut slightly since their deck is mostly blue/green rather than black, reducing its upside as a proactive protection spell in this specific mirror. Prioritize countering their Show and Tell and racing to resolve your own engine first.