Where is Orochimaru's life force bounded? Why doesn't he die like others?
First at Orochimaru's den, Sasuke tried to kill Orochimaru while Orochimaru tried to take over Sasuke's body.
Then later in the manga, during the fight between Sasuke and Itachi, Orochimaru was revealed to be partly present inside Sasuke, where Itachi dealt with him.
Now, after Edo, Itachi and Sasuke beat Kabuto. Sasuke was able to pull out Orochimaru from Kabuto.
Why is that Orochimaru can survive in different distributed forms? How is his life force immortal?
(Sasori was able to survive using puppets for his real body, but the life force was bounded to his heart, so when the heart died, so did Sasori.)
What or who can kill him permanently? (except the author)
PS : I did read the question at this question but what I am interested in knowing is different.