Annul counters Baleful Strix and Mukotai Ambusher as artifact spells, denying Dimir Control its card advantage and lifelink blocker, while Steel Sabotage counters those same artifact creatures or bounces a resolved Strix to reset the card-draw trigger. Spell Pierce is weak here since Dimir Control reliably holds up extra mana, and Sleep of the Dead and Deem Inferior are too slow and reactive against a deck built to grind with Thorn of the Black Rose and counterspells. Blue Elemental Blast and Hydroblast stay in the sideboard since Dimir Control's maindeck has no red cards. Keep the full Counterspell and Dispel suite along with the core mill-threat engine intact, since protecting Tolarian Terror and Cryptic Serpent from Snuff Out, Cast Down, and Agony Warp while disrupting their permission is the path to winning this grindy matchup.