Dimir Terror is built the same way as the Mono-Blue Terror deck, using Thought Scour and Mental Note to fill the graveyard so Tolarian Terror comes down for a fraction of its cost, with Gurmag Angler as a delve-fueled backup threat — both mechanics directly punished by exiling their graveyard. Nihil Spellbomb can blank a discounted Terror or shut off Gurmag Angler's delve entirely. Pyroblast answers any blue spell or permanent, including a resolved Terror or their Counterspell, and Envelop counters their sorcery-speed card draw like Lorien Revealed. Cast Down and Krark-Clan Shaman are cut since spot removal on a five-toughness Terror is inefficient compared to denying it ever getting cheap.