A very thoughtful thread. I enjoyed every page. However as an immoral, heathen pagan and nihilist I must not step in this moral morass.
I'd spout Nietzche till my fingers rub to the bone.
However, sorry to mention anime again but OnePiece comes to mind when considering the lifespan of heroes/villains and the option of sparing lives. And by the way I refer to the comic form, not the show. *retch*
Time and time again, every main character and most of the villains are brutally bashed or savaged and either by being spared or simply sheer pluck have revived again. All this, without Ressurection. The moral shift, from 'villain' to 'ally' might not be Good Vs. Evil but it's possible at a simple level; no charming, no 'alignment quest', no high level magic. They heal, they have a change of heart, and re-prioritize.
Probably would be handled through roll-less gaming in most campaigns, but maybe there's house rules for this?
Not many characters die in that series, even though they all take a beating within inches of their lives at some point(s).
Giving the victors more direct control over the end-result of combat, like "I'll leave them at 0 HP" rather than "Aw shit I just dealt 150 damage and they vaporized" might allow both better story continuity/development and moral dynamic.
Whether for good or evil, the option NOT to kill a character yet subdue them, and not with Subdual Damage, would allow greater distance between Those That Kill With Abandon, Those That Kill Mercifully, Those That Kill Reluctantly, and Those That Simply Do Not Kill Anyone.
Couldn't truly tell if each OnePiece character's recovery was from self-will or merely allowed by the opponent (pulled punches), but in D&D and d20 I'd like to see less dependence on magic for self-improvement.
Atonement, I'm looking at you.
Arg.. headache. Hope that made sense in some weird way