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From Pathfinder Impossible Magic, which isn't enabled.

Void Sickle

ITEM 6
Price 235 gp
Usage held in 1 hand
Bulk L
Category simple
Group knife
Damage 1d4 slashing

This +1 striking ghost touch sickle is made of an impossibly dark steel that absorbs all surrounding light, causing shadows to cling to its blade and those around it to feel an unnatural chill.

Activate—Light Harvest (darkness, manipulate, void)
Frequency once per day

Effect You swing the void sickle in a wide arc, drawing light into the blade. All non-magical light sources within 30 feet are immediately extinguished, and the next melee Strike you make with the void sickle before the end of your turn deals an additional 1d6 void damage.
Pathfinder Impossible MagicORC