Here's what I've worked our so far, this is a mix of facts from the grimorie and some other stuff I've theorized. 1. A main factor to the vex threat is the black garden 2. At some point in time, the original keeper of the garden (theorized to be the creator of our reality) was killed by an unstoppable/evil force 2B. I theorize Rasputin watched this happen, and formed an alliance with IT. 3. The black garden exists outside of space/time 3B. The black garden is actually inside the Traveler. Rasputin and IT (theorized to be the darkness) used the black garden to create the vex. 4. The Traveler has been at war with the darkness for longer than we know, possibly since the assistance of reality. 4B. The traveler already fought and lost the war, and now the darkness is using it as a "puppet" to gain access to new worlds. 5. Multiple realities do exist, and nobody knows where the Exo came from 6. The Exo stranger is involved in a very complicated shadow war 6B. (theory) This alternate universe is where the darkness is originally from.