All know that Elves cannot die, and that Men do. All know that Men go unto the Underworld upon their death, and that the Elves retire unto the Spiritual Elysium. Yet in the Great Scheme, where goes the one with one foot in the Underworld, and one foot in the Realm of Spirit?
A sword that stores the identity of the wielder. To transfuse the soul to the blade, one must first stab himself through the heart. The person will not die, but lose the freedom of the soul upon real death.