(...Okay. i really don't want an argument to flare up again, and just to keep this calm. Sure, we brought her here, but that doesn't mean we're responsible for her actions. Also look on the flip side, her side. Why would she want to kill something so much? if killing a sin as you say, and its so evil that demons are going to corrupt us without fail (even if we don't actually kill it ourselves, because besides guilt, we would bear no sin. unless sin is an area of effect thing. A merchant who sells a knife to a man who goes to murder someone isn't a sinner now, is he? ), why would a miko, a VERY holy being, want to kill a demon? from what heard and subtle wording side , its because she literally got MIND FUCKED. it brought her to the pits, it made her taste fear and bring her to her lowest. no amount of 'noooes, dont kill it, its a good person' is going to dissuade her right now. hell, I'd fail to see how you could stop her from harboring a bias right now. she WILL kill it, its just if we stand in her way or not. Both sides are NOT wrong here, as this is a VERY open ended question. a 'Paladins issue' as you will. Both sides are right, and none are wrong. Even if it sinful, if you got messed up by someone, you want revenge. When you see them, your emotions run high, and there is LITTLE anyone can do.
The demon, as far as i understand it, is just a Elemental/Conduit with a soul stuck inside. if anything, i'd see it as a soul jar, with the soul being forced to corrupt. its not mercy to let it live in MY opinion. its a hell. im sure the soul does NOT want to corrupt, but given the body itself, it was designed with a purpose. The soul is nothing more then a battery to keep the thing going. It was a soul pulled so that this thing could be a stronger servant at the cost of its torment. in MY opinion, the only way to save it is to FREE it. Look at it how you want, if you want to say its murder, fine. Perhaps you see this in a different way, or that its living so it deserves a chance. im FINE with that view point and i acknowledge it. If my assumption is correct though, the demon is NOT what you need to save. the soul is. If the case that my guess is right, The soul is not guilty of any sin, and we have done it a far greater service then to make it suffer though a body it doesnt belong in. if im wrong, the soul can be absolved of its sin in the cycle of reincarnation, which if im correct, is a MAJOR thing in Buddhism. And quite frankly, i dont see this thing being able to go though a 'treatment' per say to make it stop corrupting. leaving it alive is like leaving a man with a missing leg alive. they'll keep going, but nothing is going to change. Again, i see it as a created being with a purpose. If the purpose is accomplished, it is ether destroyed or reassigned to a new purpose by its owner/master. The design is sloppy, and has shown no regrets for its actions, meaning its creator had NO intention of breathing life into it or keep it longer then they needed. So its not designed to have extra bits like 'feelings' or 'remorse'. it only has its duty. and the soul is forced to obey.)
(Gah... sorry. okay. thats my real two cents. done and done. Please get on with it, i just want this whole sha-bamn to end.
Edit: And please no one say don't say 'oh, you haven't posted in here, your opinion means nothing'. I respect the opinions here. but if you show what i think no respect, You are clearly whats holding things up because you are a single minded totalitarian. Thats all, really.)