pf2e.fyi
From Pathfinder Adventure: Crown of the Kobold King, which isn't enabled.

Soul Chain

ITEM 6
Usage held in 2 hands
Bulk 1
Category martial
Group flail
Damage 1d8 slashing

A soul chain is a +1 striking Spiked Chain that has become cursed after a forge-spurned used it to kill a creature and trap its soul. In the hands of a forge-spurned, a soul chain inflicts an additional 1d6 fire damage on a hit. Other creatures can use a soul chain as a standard +1 striking spiked chain. A soul chain fuses with its wielder the first time the wielder damages a living creature with the weapon. A character who dies while carrying a soul chain must attempt a DC 20 Will save; on a failure, they're immediately transformed into a forge-spurned. Carrying multiple soul chains doesn't increase the DC of the save, but the carrier must attempt the save once for each chain they carry.

Pathfinder Adventure: Crown of the Kobold KingOGL