Mono-Blue Terror lives and dies on graveyard density, since Tolarian Terror and Cryptic Serpent both cost less for every instant/sorcery in the graveyard — exiling that graveyard with the extra Nihil Spellbomb resets their cost reduction and denies the payoff for all their self-mill. Duress strips Counterspell or Brainstorm before they can protect a threat, and Nausea's -1/-1 to all creatures cleanly kills a 1/1 Delver of Secrets. Fungal Infection and Grapple with Death are cut since their creature count is low and their real threats (Tolarian Terror, Cryptic Serpent) are far too big to kill with -1/-1 effects; Titan's Grave is trimmed since a tapped land is a real cost against a tempo-oriented deck.