From Pathfinder Lost Omens Ancestry Guide, which isn't enabled.

Killing Stone

FEAT 13

Prerequisites Star Orb

Your star orb hides a deadly miasma. You can cast 5th-rank Toxic Cloud as a divine innate spell once per day. The spell's normal components are replaced with a focus component (your star orb) and a somatic component to aim the orb towards the location for the spell.

Pathfinder Lost Omens Ancestry GuideOGL