Mono-Blue Stiflenought plays no red spells, so Hydroblast has nothing to hit and stays boarded. Naturalize comes in as insurance against Powder Keg, which can otherwise wipe our small creature base once it reaches the right fuse count. The extra Raven Familiar smooths draws toward assembling Aluren faster, since this matchup is a race against a deck trying to land and protect a turn-one Phyrexian Dreadnought. Bone Shredder is a weak cut since Dreadnought is an artifact creature and dodges its nonartifact restriction anyway; Sylvan Library's life payments are also risky against a deck that can close quickly with an unanswered 12/12. Man-o'-War remains our best answer, bouncing a resolved Dreadnought before it can attack.