Entropic (3.5e Equipment)
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Upon speaking a command word, an entropic weapon is charged with negative energy, and remains active until the command word is spoken a 2nd time. Upon striking the weapon deals 2d6 negative energy damage and the target must make a Fortitude save DC 14 or gain 1 negative level. Additional hits do not bestow additional negative levels, they instead refresh the duration unless a critical occurs in which case the target is granted a additional negative level to a maximum of 2. A critical hit deals 2d10 negative energy damage (3d10 for x3 and 4d10 for x4) and grants 2 negative levels. Undead that are struck with a entropic weapon are healed instead as well as gaining 1d8 temporary hit points for 1 hour (2d8 on a critical hit), again additional hits do not stack, instead refreshing the duration. This property cannot be applied to ammunition.
(Major Necromancy) Caster level 20, Caster must be evil, Craft Magic Arms and Armor , Greater Harm , Energy drain , Lesser Entropic, Price +5 bonus, Must be crafted in a minor negative energy-dominant area, i.e. Darklands, Doldrums.