pf2e.fyi
From Pathfinder Lost Omens Shining Kingdoms, which isn't enabled.

Hungry Blade

FEAT 12
ARCHETYPECONCENTRATE
Activity 1 action
Archetype Splinter of Finality
Prerequisites Spectral Dagger
Frequency once per day
Requirements Your previous action was a Strike with your spectral dagger that dealt spirit damage.

Once your spectral dagger has tasted an enemy's soul, your splinter of finality becomes increasingly relentless in its attempts to claim the soul. Your spectral dagger gains the effects of a Keen property rune that applies only to Strikes against the target of the required Strike. This effect lasts for 10 minutes or until that target dies, whichever comes first.

Pathfinder Lost Omens Shining KingdomsORC