Grixis Reanimator wants to fill the graveyard with Faithless Looting and Thought Scour, then bring back Archon of Cruelty or Emperor of Bones with Unearth or Persist for a fast, disruptive threat. Endurance is a premier answer, exiling their graveyard for free to strip away Unearth and Persist targets while replacing itself. Orim's Chant protects your own combo turn or stops their reanimation spell at a critical moment. Postmortem Lunge is actively bad since it feeds a graveyard-based opponent, and Ouroboroid is too slow against their disruptive, tempo-positive draws built around Psychic Frog and Thoughtseize.