Hmm... Extreme moral opposites? I was more under the impression (from what was discussed at some point in the OldGuild OoC) that the dead would be separated to the two sides based on some rather ambiguous line between "more evil than good" and "more good than evil" that furthermore depends on the judgment of the surrounding people ... which would essentially mean that the people on the Upper Plane would be better than those sent to Lower Plane, but far most of the people on either side would not be anything even remotely close to representatives of either pure good or evil respectively. Back then you furthermore said that it perfectly possible for a person on either plane to commit deeds which make them tip over to the other side (but they wouldn't be "judged again", so they'd just stay there as people of the other alignment). - And that is not even delving into the matter of good and evil being rather subjective things, which they ultimately are. 

And yeah... As I have mentioned it before, the concept of angels and demons is rather disturbing to me personally. The manner in which they are created, that is. "You do not have to kill the body to kill the person", or in this case, you do not have to destroy the soul to kill the person. Look at it as I might, I cannot see the process of becoming a demon or angel as anything else but one of the very few ways to achieve final death in a world wherein a person can be other than the body and a spiritual suicide. A person who simply has forgotten all is still the same person - the ... way things are processed, the personal kind of logic, the base personality, all those things and then some remain when memories are gone, after all. With the lesser immortals, these things do not stay from what I recall. (Which would make them much less of the same people than even the [i]karakon[/i] are.) It would take quite the emotional overcharge and ... yeah, quite a lot to opt for something like that rather than simply a way of forgetting or overcoming and moving on, and possibly a different image to avoid being recognized. The Upper and Lower Plane have to be immense to accommodate for the people of all ages, after all, and avoiding your past shouldn't be too much of an issue. Angels are truly a sad testimony...
The entire concept of afterlife is built around (the hope of) living on past the obvious death of the body. Granted, there are many incarnations of it, and I haven't really seen one which I have considered preferable (quite often the opposite - the afterlife is notably less desirable) to simply living on in the mortal world. You can make a truly beautiful and perfect world for all the good people, but in the end simply living under easy conditions without nothing to fight for tends to lead to indifference and monotony. It is not my own conclusion here - many before me have said the same, many books have been written over the concept of all utopias being doomed to collapse for that exact reason, all scientific research I've seen has basically reached the same conclusion (though spending all on just surviving hinders progress the same) -, but I, too, feel I would rather accomplish something of significance than move on to some "perfect" plane of existence. Improve the world - even by small things such as helping a person or a two where I can - and all that. That much of an idealist I am, I suppose. 
...Then again, it is perhaps the reason why immortality is a condition pursued by so many people of Reniam despite afterlife being a widely-accepted fact rather than a fairy tale or something people only hope or believe to be true, but cannot prove or know for certain. 

(The line of "you do not have to kill the body to kill the person" I occasionally cite is from a book. - Sciencefictional scenario wherein many members of a culture that had long developed independently were forced into surrendering, after which they had their brains completely rewired to cover up the existence of the culture for the people who were not supposed to be aware of it, with memories and personalities and everything else being redone. The protagonist got to speak to one individual both before and after, and that experience was quite terrifying on a level you do not exactly see often in actual "horror", although with me it is one of the things which might make me actually think for a bit and register as uncomfortable.
The author as a writer is ... okay, but barring two specific reoccurring themes which I disagreed with - again, subjectivity or right and wrong, good and evil and so forth -, there were quite a few good ideas and notions I agreed with. None of his books, sadly, have been translated to English, or any other language...)

 - Various other versions of afterlife that can be found elsewhere? Outside of the world of the Prophecy, I presume?
(As a random note, I briefly thought of a character that is reborn again and again (not quite in the Buddhist sense, though there would have been some inspirations otherwise - in Buddhism the "self", "I" whatever you wish to call it actually does die and only some a bit harder to define part moves on), but this one would probably have been even harder to fit in the world than Aemoten ...atop of the fact that he would not have been a fighting character. I am still slightly tempted to NPC him. Would also have him speak Sanskrit as his native language, just cause - you see Latin come up very often in (western) fantasy settings, but very rarely Sanskrit or something more exotic.)