Nicodemus Archleone's noose

Nicodemus Archleone carries a noose at his neck, which gives him access to certain kinds of magic.

Description
Believed to be the noose Judas used to hang himself, it is a powerful magic object, capable of death and entropy curses.

Death Masks
In Death Masks, the noose allows Nicodemus Archleone to cast a Barabbus curse against Harry Dresden.