pf2e.fyi
From Pathfinder Claws of the Tyrant, which isn't enabled.

Cut them Down, Burn them Out

FEAT 18
Activity 1 action
Prerequisites Knight Reclaimant Dedication; master proficiency in a weapon

Inspired by the sixth line of the Crimson Oath, when you oppose the enemies of Lastwall, you aim to excise the rot from the land itself. Make a Strike against an undead creature using a weapon with which you have master proficiency. On a success, in addition to the attack's other effects, the creature takes a –2 status penalty to the DC of any curses, diseases, or poisons it can inflict for 1 round. On a critical success, the undead creature takes the –2 status penalty for 1 round, then a –1 status penalty for an additional round.

Pathfinder Claws of the TyrantORC