Dimir Terror mirrors the self-mill plan of Mono-Blue Terror, using Thought Scour and Mental Note to fill the graveyard for a cheap Tolarian Terror while also enabling Sneaky Snacker to return from the graveyard after a third card is drawn in a turn; Relic of Progenitus attacks both of these graveyard-dependent plans at once. Pyroblast counters or destroys their blue spells and permanents, and can answer a resolved Tolarian Terror if you pay the {2} required by its Ward 2. Cut Pulse of Murasa, Campfire, and a Bonder's Ornament, which do little against this tempo-oriented graveyard deck. Hold up Counterspell and Dispel to protect your own plays from their matching permission suite.