There is also the ring-bearing possibility (not to my liking though

):
Quote:
Originally Posted by FotR, Shadow of the past
A mortal, Frodo, who keeps one of the Great Rings, does not die, but he does not grow or obtain more life, he merely continues, until at last every minute is a weariness
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Just as in Mouth of Sauron's case, Sauron could give his wraiths the ability to overcome this weariness.