This is a combo matchup where Sultai Aluren wants to resolve Show and Tell into Atraxa or Omniscience, or land Aluren, so Force of Negation is a premium free counterspell to stop these noncreature spells on their turn before the engine goes live. Consign to Memory can only counter triggered abilities and colorless spells, so it will not stop Show and Tell, Aluren or Omniscience. It does answer the enter trigger on Atraxa and the attack trigger on Acererak, and it can hit their Lotus Petals. Replicate lets you pay extra to copy it if needed, and it's cheap enough to hold up while still digging with your cantrips. Into the Flood Maw and Unholy Heat are reactive creature answers that do little to stop the spells that start their combo, and Spell Pierce can simply be paid for with their mana and Lotus Petals, so those three come out along with a Preordain to make room. Prioritize racing fast with Dragon's Rage Channeler and Murktide Regent while holding countermagic for their key enablers.