From its purpose to its origin, the Soul Stone has been a major point of contention and discussion for several years in the fandom. In Avengers: Infinity War, the Soul Stone is revealed to be hidden a far-off planet no one has ever heard of, guarded by the villain formerly known as the Red Skull, and payable on death and death alone. Some of the stone’s capabilities are showcased in Thanos’ stand-off with Doctor Strange when the sorcerer creates multiple versions of himself, only for the real Strange to be located by the stone. In a recent Q&A, the Russos shared some insight on its ambiguous nature.
The Soul Stone has the ability to manipulate your soul and your essence of who you are. Thanks uses the Soul Stone to pull Strange out of his own body when he’s multiple Stranges. Thanos also uses the soul stone to talk to his dead daughter.
— Peter Sciretta (@slashfilm) November 29, 2018
Many fans believe that the Soul Stone houses the lives of those decimated by Thanos’ snap. The Russo’s comment about the stone manipulating an individual’s essence certainly lends itself to the visual of someone disintegrating. Also interesting is the idea of Thanos deliberately using the stone to talk to Gamora in the afterlife – or could it be the other way around as Red Skull describes the stone to have a certain wisdom among the six stones. Whatever the stone’s full potential is, I do believe that it’ll be the most significant stone of them all, come Avengers 4.