Dimir Terror mirrors Mono-Blue Terror's graveyard-fueled cost reduction on Tolarian Terror, protected by Counterspell and Snuff Out, so Duress is the priority sideboard card, taking away a counterspell or removal spell before it can protect their threats or answer yours. Sneaky Snacker returns itself from the graveyard once they draw a third card in a turn, which graveyard hate like Nihil Spellbomb reliably stops by exiling it from the graveyard. Tithing Blade adds cheap removal, while Grim Bauble and Candy Trail are cut to make room for targeted hand disruption and edicts against their threats.