Dimir Terror wants to fill its graveyard with Thought Scour and Mental Note to cheat Tolarian Terror and Gurmag Angler into play, so Remove Soul is a premium answer that stops those threats before their cost reduction or delve makes them efficient. Last Breath exiles a cheap Sneaky Snacker before it can return to the battlefield from the graveyard off a third card drawn in a turn, and exiling denies that recursion entirely rather than just killing it. Their Snuff Out can answer our creatures for free off a Swamp, so lean on Ephemerate and Ghostly Flicker to protect key value creatures like Sea Gate Oracle and Archaeomancer from removal. Bring in the targeted answers over our own generic counterspells since precision matters more than card quantity in this grindy mirror-style matchup.