[Spoilers] Amnesia Plot

[kastanok]

I gather Alexander extended his life by extracting the 'vitae' from living creatures, in a process which required invoking absolute terror in his victims. In the private chamber above the Transcept (or was it in the study with the stuffed animals?) there is a note in which Alexander discusses the suitability of humans for this purpose as they are capable of truly anticipating the coming experience.

That 'going home' phrase got my attention too. Perhaps, while being born on this plane, on Earth, he now considers himself to be beyond human and that he, or his soul, his essence, is 'returning' to his rightful home.

The darkness, as you call it, is the Guardian of the Orb. One of the loading screens I think mentions that Daniel theorises the Guardian is the universe acting to restore the orb to its rightful place. Why is it there, what does it do? Who knows.

Just some theories.