Grixis Reanimator uses Unearth to cheat back mana value 3 or less creatures and Persist to reanimate nonlegendary creatures, targeting huge payoffs like Archon of Cruelty, alongside Psychic Frog which needs to exile cards from the graveyard to gain flying. Tormod's Crypt answers all of this at once — exile their graveyard to strip Unearth and Persist targets and deny Psychic Frog's graveyard-exile activation. Unholy Heat kills Psychic Frog while it's still small and can scale to 6 damage with delirium to answer a reanimated Abhorrent Oculus. Bring these in for Lava Dart, Violent Urge, and a Mutagenic Growth, since proactive graveyard disruption is far higher-impact than marginal pump or a weak flashback burn spell here.