Ok so I was just looking around on the forums when I saw a post that made something click inside my head. In Halo 4 the Didacts ship was a semi-large sphere. I know Halo and Destiny don't have anything similar as far as the story line goes but what if inside the Traveller there's a forerunner type being that was strong enough to fend off The Darkness long enough to get to Earth and there is a power radiating from the forerunner type being giving the guardians their special "space magic"? Or the forerunner being is choosing certain heroes (guardians) to protect it while it comes back to full life? I don't know for sure it's just a theory please do discuss im wondering what the community has to say about my theory.
I made a joke about the Didact coming back to Earth on the Bungie Weekly Update post.