Sultai Aluren wants to assemble Aluren plus cheap creatures, or Show and Tell into Atraxa/Omniscience. Tormod's Crypt is mediocre against Aluren itself, but it is a free artifact for your affinity costs and gives you a way to exile a graveyard if they bring in graveyard-based cards after boarding. The second set of Force of Negation is crucial since this deck is light on ways to interact once Show and Tell or Aluren resolves, and countering their noncreature spells such as Aluren, Show and Tell, Omniscience or Stock Up on the stack is far better than trying to deal with them after. Keep in mind that Force of Negation can't hit creature spells like Atraxa or Acererak, so those need to be handled with Force of Will or other interaction. Chalice of the Void set at one is already strong against their cheap card-selection and protection, such as Ponder, Brainstorm and Veil of Summer, so lean further into proactive disruption and cut the slower bounce-based Sink into Stupor copies, which only set back an Aluren or Omniscience that's already on the battlefield instead of stopping it the way hard countermagic does.