Preliminary trope definition: When the "Jar" in Soul Jar
is an actual living person.
- The Sanjiyan Unkara to their Wu servants in 3×3 Eyes.
- Naraku, Big Bad in the series InuYasha, treats Inuyasha as little more than an annoyance early in the series. However, as Inuyasha gains power and becomes a real threat, Naraku -- who is an amalgamation of hundreds of demons -- splits off his heart in the form of an infant, which he hides away under the protection of another of his incarnations, making him effectively immortal.* In Harry Potter, Harry himself is Lord Voldemort's sixth Horcrux. Another example of this is Nagini the snake who is Voldemort's seventh Horcrux.
- In Darkstalkers, Morrigan is not only a Soul Jar for her "sister" Lilith (justified in that the two were Split at Birth; Lilith is 1/3 of Morrigan's soul having gained sentience), but for all of the souls she's ever taken in order to keep herself alive. The latter are not destroyed, but live on within her body in eternal bliss, taking the form of the bats Morrigan wears around her body.
- In Kingdom Hearts, Sora is carrying Kairi's heart within him. Additionally, in Birth by Sleep, it's revealed that Terra holds the heart of Master Eraqus inside of his own, as discovered by Master Xehanort (the one who struck down Eraqus) when the two are chatting inside of the heart of Terra-Xehanort, the present-day Xehanort.
- In Percy Jackson and the Olympians, it's revealed that Luke had become one of these for Big Bad Kronos.