[Spoilers] Amnesia Plot

[Karkarov]

Well here is what I can tell you for a fact based on in game things.

Alexander is not human, he was banished here from the other plane. Why was he banished? Hard to say, I bet it had something to do with him doing very psychotic bad things though. He mentions a lost love in his "memory capsules" and even says humans are little better than dogs where he comes from. Well he is gone for hundreds of years so I suspect his love has probably gotten over him by now regardless.

Johann Weyer. Long story short do some real research. Agrippa and Weyer are both real people that had real lives. Agrippa was a big time occultist and studier of medicine and such who was rumored to practice witchcraft/devil worship. Weyer was his student who basically surpassed him in every way and furthered his studies. So we can assume in game terms Weyer being a sharp cookie simply figured out how to actually control the orbs which would in effect enable him to make short work of the "shadow". Agrippa and Alexander both say in the game without the orbs power you can't fight the shadow...

Now that we are talking about the shadow... a note of Agrippa's lays it out plain and simple. They are just the guardians of the orbs. Are they physical beings? Uh no, you see in game that the shadow is literally a shadow not a "creature". It simply corrupts and or destroys whatever it effects through some type of metaphysical energy or power. Hence puss sacks growing out of walls and people dissolving in mid air into showers of blood. It is not intelligent or "alive" however... It is more like a protection feature or security protocol to prevent wrong usage of the orb. In other words it is a really nasty anti virus app.

The orb, Alexander tells you what it is in one of his notes though he doesn't spell it out or specifically say that what he is talking about. It is a power source/control device for a traveller's locket. Basically it is one half of an item used to travel between different worlds. Yeap, it is that simple.