Lifedrinker
From AmtWiki
A relic from By Night They Dance.
Description
Once per life, the wielder can awaken this weapon’s evil spirit, and make it equal to an Imbued Weapon for a 50 count. If the wielder has not taken the life of someone within the 50 count, the weapon will automatically take the life of the wielder. Like Mutual Destruction, nothing can prevent the wielder from being killed in this way if he fails to ‘feed’ the weapon. Lifedrinkers cannot harm Undead.
The type of the weapon (i.e. short weapon) is not specified in the literature.