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

Shadow Blending

FEAT 1

Activity reaction

Trigger A creature attempts a flat check to target you while you're Concealed or Hidden due to dim light or darkness.

You draw shadows close to create a shroud. Increase the DC of the flat check by 2.

Pathfinder Lost Omens Cheliax, Infernal InheritanceORC