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

Breath of Calamity

FEAT 17

Your roar shakes the earth and splits the heavens. Once per day, you can cast Chain Lightning as a 7th-rank innate occult spell. Any creature that critically fails its save against the spell is Blinded and Deafened for 1 round.

Pathfinder Lost Omens Impossible LandsOGL