I just re-read Picture of Dorian Gray and it occurred that the portrait was similar in many ways to one of Voldemort’s horcruxes: it held a part (or the total) of his soul, its destruction was necessary for his own and thus conveys some degree of immortality to him, and it’s created by essentially dividing his soul and later cemented by murder (first and second degree) as well as riotous dissipation.
Davy Jones’ heart in Pirates of the Caribbean is similar as well; he cannot be destroyed- at least not easily- so long as his heart is intact.
What are some other horcrux like devices in fiction?