Rest in Peace is the premier sideboard card against reanimator strategies, exiling all graveyards on entry and preventing Reanimate, Animate Dead, and Shallow Grave from ever functioning, while also stopping their Cabal Therapy flashback. Containment Priest exiles any nontoken creature that enters without being cast, directly answering Griselbrand, Atraxa, and Archon of Cruelty coming in via Reanimate or Animate Dead. Surgical Extraction can proactively exile their Reanimate or Animate Dead copies once one hits a graveyard, denying the backup plan. Force of Negation and Spell Pierce come out since our best plan is denying the reanimation target itself rather than countering noncreature spells, which they can often play around via Unmask's alternate cost.