Dimir Terror mills itself with Thought Scour and Mental Note to power out a cheap Tolarian Terror, delve into Gurmag Angler, and recur Sneaky Snacker from the graveyard on their third card drawn each turn. Relic of Progenitus directly attacks all three of those graveyard-dependent plans, and its sacrifice mode can wipe the yard right as they're setting up a big turn. Red Elemental Blast trades with a resolved Tolarian Terror or counters their Counterspell. Journey to Nowhere is less exciting against their cheap, replaceable threats, so it steps aside for the more targeted graveyard and blue hate.