The Cosmic Divining Rod has been used both by Black Hand and Atrocitus. The device has the ability to detect and drain a Green Lantern's energy. It can then fire this energy in destructive blasts.
The Cosmic Divining Rod was created by Atrocitus of the Five Inversions, who planned to use it to guide him to the being prophesied to bring forth the Blackest Night, William Hand. It would also be used to store the power of 'the Black' upon Atrocitus' return journey to Ysmault. Locating William at the Hand Family funeral home, Atrocitus was defeated by Green Lanterns: Sinestro and Hal Jordan. Atrocitus dropped the Rod, however, and Hand pocketed the device during the struggle.
Years later, William Hand would go on to use the device against the very person who saved his life, Hal Jordan. Though his attempts at villainy would be met with failure, much like most things in his life. However, Atrocitus was right to believe Hand would bring forth 'the Blackest Night', for on that same day the two crossed paths, William had made contact with an unseen force. It was this force that inspired William to run after picking up the Cosmic Divining Rod.
Throughout the years, William's use of the Rod and his communion with the unseen voice would continually increase until William Hand was prompted to do that which most people would find inconceivable. Delusional from lack of sleep and the increased contact with 'the Black', William Hand returned home and, with the Rod in hand, murdered his entire family before turning the device upon himself.
Visited by a being known as the Scarred Guardian, a black ring slipped itself upon the dead man's hand whereupon the body arose. The Scarred Guardian proclaimed William to be the Black Incarnate, the herald of the unseen force with which William had communed with for so long. "William" exclaimed he knew what he was and with the power of the black, 'he' would finally destroy the light.