pf2e.fyi
From Pathfinder Lost Omens Cheliax, Infernal Inheritance, which isn't enabled.

Inflict Punishment

REACTION
Activity reaction

Trigger You are hit with an unarmed Strike or a Strike with a non-reach melee weapon
Frequency once per day

Effect You twist your body so that the attacker hits a hard edge of bone or armor, injuring themselves. You deal 1d8 per 2 levels piercing damage to the triggering creature (basic Reflex save using your class DC or spell DC, whichever is higher). At 3rd level, and every 2 levels thereafter, this damage increases by 1d8.
Pathfinder Lost Omens Cheliax, Infernal InheritanceORC