Ability Drain and Damage as Weapon Abilities (PEACH)

Saw this idea posted in another thread designed for 3.x, and decided to take a "stab" at it for Pathfinder. This is basically just a rewording of the 3.x Wounding weapon ability:

Weaken – A weakening weapon deals 1 point of ability damage each time it hits a creature. Which ability is affected is chosen at the time of weapon creation and cannot be changed. A critical hit does not multiply this damage. Creatures immune to critical hits (such as plants and constructs) are immune to the ability damage dealt by this weapon.

Moderate necromancy; CL 10th; Craft Magic Arms & Armor; Bestow Curse; Price +2 bonus

Vanquish – A vanquishing weapon deals 1 point of ability drain each time it hits a creature. Which ability is affected is chosen at the time of weapon creation and cannot be changed. A critical hit does not multiply this draining. Creatures immune to critical hits (such as plants and constructs) are immune to the ability drain dealt by this weapon.

Strong necromancy; CL 15th; Craft Magic Arms & Armor; Bestow Curse, Greater; Price +3 bonus

So under this method, it would be possible to have up to six different ways to build a weapon, one for each ability, or you could stack two or more together on one weapon for a really nasty effect.

Apologies if this has already been done better somewhere else.
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