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From Pathfinder Lost Omens World Guide, which isn't enabled.

Necromantic Tenacity

FEAT 8
Archetype Lastwall Sentry

Your training against necromantic effects allows you to escape the worst of their touch. If you roll a success on a saving throw against a necromancy effect, you get a critical success instead; if you roll a critical failure on such a save, you get a failure instead.

Pathfinder Lost Omens World GuideOGL