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

Cracked Mountain

FEAT 12
Activity reaction
Frequency once per hour

Trigger You would be reduced to 0 Hit Points but not immediately killed.
Requirements You are in Tenacious Stance.

You fight on, staying on your feet and lashing out at a foe. You avoid being knocked out and remain at 1 Hit Point, and your Wounded condition increases by 1. Make a melee Strike at an enemy within reach. You immediately end your Tenacious Stance.

Pathfinder Lost Omens HighhelmOGL