Note: MJ, I'm doing better now, so unless you really want to you don't need to reply to my email.
Let us consider a discrepancy in Multiverser rules and the world of fiction. In 'Angel' on TV, Fred the Genius Girl is sacrificed and her soul is 'burnt up in the fires of ressurection' to make Illria, the Greatest of the Ancient Demons come back. In one of David Weber's stories an evil magic sword has a sacrificed and broken and damaged soul trapped in it. In Ringo's pretty good 'Princess of Wands' about a Southern Baptist soccer mom demon hunter if you die facing off against a demon it gets your soul. There are questions as to whether you might be freed at the end of time.
However, in Multiverser it clearly states that the Anarch powers have no ability to confine an Alliance soul.
I like Multiverser's stance. I think of Ringo's idea as one of the flaws in his rather neat book.
There are also stories about souls trapped as ghosts until some evil spell is lifted, or until justice is done.
One of the theories of ghosts offers a way of resolving this. It says that ghosts are not sentient spirits, but memories embodied in matter.
I had come up with an exceedingly cool end to a book I've never finished. The villainess is a well-meaning sort tormented by guilt which drives her to her villainy, and while she asked for forgiveness, she didn't believe she had received it. She believed enough to ask, which was enough, but not enough to put her guilt behind her. In the end, the hero is triumpant, and she's dead. She waits in the Gray Plains to be picked up by her god, and she is covered in shackles. Her god shows up to take her to Paradise, but she refuses because of her sins. So he reaches into her her mind, removes all her memories, and stuffs them into his pocket with the thought that he might return them to her in ten thousand years when she is stronger. She then happy like a little girl skips to join him.
Thus perhaps the answer is in part 'memories'.
There are also stories about souls trapped as ghosts until some evil spell is lifted, or until justice is done.
Let's not forget Casper. In that movie, they had to complete their unfinished business.
The anarch powers cannot keep you trapped in the anarch realms of the supernatural. Multiverser does not say that your spirit cannot be trapped in a physical object, nor that your body cannot be possessed by a spirit. There are ways that this can happen--and be undone.
As to a demon consuming your "soul" ("spirit" would be the word I prefer for this), you've got the neat protection that in order to pull your spirit out of your body it must kill you, and if it kills you you travel to another universe, so it is deprived of its repast. (The same thing is true if a dragon eats you: you die, but come back in another universe, so it is still hungry.) That does not mean that the demon can't consume the spirits of mortal beings; Multiverser does not answer that question because, frankly, the player characters are not those mortal beings and can never know the truth of the matter directly.
--M. J. Young
M.J. - Can't a spirit theoretically keep your body alive (say, by possessing it, or having one of its minions possess it), and then bottle your soul to do with as it pleases? Your body remains 'alive' with all of your Bod skills at its disposal, while you (ya poor bugger) just became Errtu's new paperweight.
John--yes, but it cannot kill your spirit, and your spirit takes with it all your magic, psionic, and technological skills (as well as having the examples of your body skills if you need to learn them in a new body), so Errtu may have bitten off more than he can chew ultimately.
Particularly, if he did this in a high mag world (almost a must) and you've got a high mag bias, it's not going to take too much for you to develop a few mag skill that don't require you to do anything. After all, how long can you invest in that prayer for the avenging angel to come to your assistance? Maintain the prayer for a few days, and the fact that you have no verbal, material, or somatic components will be compensated by the extended time factor. There are probably a lot of things you can do magically and psionically from inside that bottle.
Sure, your captor is going to put defenses against you doing anything at all; but then, that becomes a battle of your power against his, and even if he has a lot more power, you have a lot fewer other concerns to address with yours.
What the spirit cannot do is destroy your spirit. It can't destroy your body, either--it can only verse it out, in which case your spirit is the absolute property of your body and goes with it, even if that means it has to take that three thousand foot statue in which it is entrapped with it. (And boy, if you can manage to animate that three thousand foot statue, your captor might wish he'd thought of a different prison.)
--M. J. Young