pf2e.fyi
From Pathfinder #191: The Destiny War, which isn't enabled.

The Survivor

ITEM 20
UNIQUEARTIFACTHARROW-COURTINVESTEDMAGICAL
Usage carried
Bulk —

Suit Shields (Con)

Alignment neutral good

The Survivor represents rebirth through ordeal. When you have The Survivor invested, you gain Diehard as a bonus feat. If you already possess this feat, you gain a +2 item bonus to all recovery checks. This item bonus increases to +3 if you are at least 17th-level.

Activate envision
Frequency once per day
Trigger you are reduced to 0 Hit Points
Effect You somehow manage to survive what could have been a fatal blow. Instead of being reduced to 0 Hit Points, you drop to 1 Hit Point instead and immediately restore an additional 4d8+16 healing Hit Points. The amount of Hit Point restored increases to 5d8+20 healing if you are at least 15th level, 6d8+24 healing if you're at least 17th level, and 7d8+28 healing if you're at least 19th level.
Pathfinder #191: The Destiny WarOGL