Unlike many of our more sweetness-and-light counterparts, we professional antagonists aren’t afraid of final solutions. People who cause us trouble often find that nothing short of narrative immunity will be enough to prevent significant decreases in their projected, if not actual, lifespan. And once they’re gone, we generally figure “out of sight, out of mind”, at least as our official policy. That is, until they come back to haunt us, figuratively or literally.
Now, we all know that with all but a near-negligible fraction of the population, just about all our ends-of-story (as opposed to defeats) are tied to having killed someone, the protagonist latching onto that, and so on. But consider this. One in thirteen Hands of Darkness meets her eventual permanent downfall due to the direct, beyond-the-grave influence of one of her old victims (and no, resurrected heroes do not factor into this statistic), and one in seven meets her end through admitting responsibility for the death of one of her victims in front of someone who has both the means and the dramatic momentum to do something about it.
If you’re in a world where resurrection is nonexistent and the dead don’t leave remainders, you’re probably not going to be one of the one in thirteen. I’d still scrub out your foe’s old data archives and burn his diaries, just to be safe. But if you have the potential to be one of those one in thirteen, now’s the time to start thinking about avoiding it. In most worlds, there are ways of forestalling resurrection or preventing the creation of ghosts; if you can’t do that, or for some reason you don’t want to, consider trying to arrange to resurrect the guy or create the ghost first so that it’s on your terms. Become familiar with the methods for all of the above, and if there is a decent chance that your enemy would be trouble if she came back, use them. Otherwise, you never know when one is going to haunt you to insanity, sic his son on you, or come back from the dead and recreate her demise on you. You have been warned.
Then there’s the one in seven, the ones who blow their own careers. I find most of them fall into two categories. The first are properly trapped in confessions by silver-tongued deceptive protagonists (or occasionally blab to normal Shining Hero types, but with those either the hero got lucky or the Hand doesn’t know when not to monologue). For them, avoidance is straightforward, if not easy: know your story ahead of time, internalize it, rehearse it, and know how not to be caught by a lie detector.
Then you have the second type, the more tragic ones. They don’t need to be talked into confessing. No, instead they see something. It might be an illusion, it might be a person with a passing resemblance, it might be a trick of the mind, some have even reported somebody accidentally putting together a disguise in a probability-defying manner—what matters isn’t so much what it was as what they saw, and what they saw was someone they’d been directly responsible for the premature death of. And the result is almost invariably the same: “You/he/she can’t be alive!” followed by some sort of incriminating comment, like “I killed the [pejorative] myself!” or “I watched you die!” (The majority of these comments used to be “Nobody could have escaped that!” and “But we saw the body!”, but those have been falling out of use since we started holding important kills to quality control standards.) Not that bad, except that this situation seems to have a Law of Dramatics all to itself, and that Law is “If they say it, someone they don’t want to hear it will.” In this case, usually someone who was not, in fact, aware that that Hand was responsible for that death. Only—well, protagonist, narrative immunity, and probably a Defender of the Innocent, a grudge-holder, or a person who’s a close friend to one or both of the above. (Powers help you if it’s all three at once.)
Not a good thing.
I’m not going to give you specific solutions; everyone’s psyche is a little bit different, and that’s going to affect what works and what doesn’t. But in general, you need to desensitize yourself to this possibility. If you think you might be a paranoid (a healthy trait, regardless of what other people think), accustom yourself to, well, seeing dead people. After enough run-ins with what appears to be former victims or friends’ former victims or former friends’ victims, you’ll probably not consider it any more remarkable when you think you see that barwench from way back when on the other side of a crowded room, and while you’ll recognize the potential problem, you’ll be able to act rationally. If the victim and/or the kill had an emotional significance to you, try to find ways to dull it; guilt, fear and hatred may be good for bringing people to the Dark Side, but they’re not so good for keeping them sharp once they’re there.
It’s bad enough when someone else’s dead walk all over you, but when it’s your own dead, it’s much worse. Try to keep them back in the grave and out of your hair where they belong!