SRD:Mindfeeder

Mindfeeder: All feeder weapons have a special ability that functions only upon scoring a successful critical hit. A mindfeeder weapon grants its wielder temporary power points equal to the total lethal damage dealt by a successful critical hit. The wielder must decide to use the mindfeeder ability after successfully confirming a critical hit, but prior to rolling critical hit damage. These temporary power points last for 10 minutes. The wielder may not exceed his natural maximum power points per day using the mindfeeder ability. The wielder gains power points even if the target has none (effectively, its hit point damage is converted to power points). Constructs and undead are not subject to mindfeeder weapons. As with temporary hit points, temporary power points do not stack with each other; they overlap. Thus, if a mindfeeder weapon successfully scores a critical hit while the wielder still enjoys temporary power points from a previous critical hit, the wielder gains only the better of the two values: either her current number of temporary power points, or the new influx of temporary power points, whichever is higher.

Strong psychometabolism; ML 15th; Craft Psionic Arms and Armor, psychic vampire; Price +3 bonus.