Board Thread:General Discussion/@comment-3134600-20140811224344/@comment-27.0.65.235-20140823125327

I agree with the Keyblade Master XIII. Let's take a look at the known capabilities of the Soul Gem:

Powers
(Copied from Marvel Comics Wiki)
 * The Soul Gem is sentient; it has a desire to collect souls
 * The gem can attack another's soul in various ways
 * The gem can reveal information by peering into another's soul or using the 'Cold Light of Truth'
 * The gem can trap souls inside itself in an idyllic world.
 * The gem's wielder can access the memories and skills of those imprisoned within Soul World
 * The gem can revert beings to their natural state.
 * The gem protects its wielder from soul-based attacks.
 * The gem can disrupt the anima of a soul with a karmic blast rendering the target temporarily unconscious. Certain beings are immune to this attack.

The most interesting ones on their which I think we have seen in this current generation of Marvel Films are:

"The Soul Gem is sentient; it has a desire to collect souls " - It possesses people, check.

  AND

"The gem can revert beings to their natural state. " - Reverting things to their natural state. Some believe that our Universe came about by random matter (regular, dark, anti, etc) being compressed by gravity into a concentrated point which 'Big Bang-ed' into reality. So the Soul Stone is trying to turn everything back into it's natural state, which is apperently Dark Matter.