These are cool theories. I agree that the darkness follows sword logic. Basically, the darkness has achieved what toland has described as the perfect shape, which is that nothing in his universe exists without him willing it. That's why the darkness is attempting to pass into our dimension, since he has already conquered everything in his own dimension. The way I see the future story, both the traveller and the darkness have to die in order for our universe to be free again and mankind to control its own destiny. The traveller is sleeping now, but once it wakes up, it will attempt to control our will, which it might be able to do since we are resurrected beings filled with his light. I figure that uldren or Mara sov along with Rasputin are predicting this and already have a plan in place to free the guardians from the traveller, which probably involves doing something to the ghosts.