Lifecutter
From Syra D&D Wiki
Lifecutter is the scythe of Nerull, the god of death. It resembles a gnarled staff of ebony with a curved blade of blood-red energy, and possesses the power to steal the souls of those it slays, giving their power to its wielder. During the Deity War, Nerull used it to steal the souls of other gods, increasing his power dramatically.
It was thought lost after his death, until a band of adventurers found it embedded in a wall in an ancient temple of Boccob deep within Estorium. Unfortunately, the wizard Tephra used Lifecutter as a focus to open a portal to the Far Realm, and the scythe was pulled through. It was seen in the hands of a massive aberrant creature shortly before the rest of the adventurers fled.
Tephra later promised the scythe to the demon lord Orcus in exchange for his help.