Ed appeared in a black void. However, this void was unlike his own consciousness he often appeared in when meditating. Instead, it felt as if his soul had been sucked into someone else's consciousness.
The void was silent and still, with seemingly nothing existing at all. The only thing that was present was an odd chaotic energy. If this wasn't just a vision, then Ed believed the energy would tear him apart in an instant. When he looked at it, an instinctive fear took over. It was by far the most violent thing he had ever felt, with not even Mr. Sai's powers coming close to it.
So, obviously quite a bit of mythical/religious themes here. We'll see similar stories in the future from Greek, Indian, and Christian perspectives. I know humans really originated in Africa by the way =p. Who knows? Maybe the other cultures will disagree with the 'nonsense' Yu the Great preaches?