Sometimes, ideas leap fully-formed into my head.
Aura strong conjuration; CL 12th; Weight —; Price +2 Bonus
A slaying weapon functions as a bane weapon that also deals additional bonus damage upon striking a successful critical hit against the weapon’s designated foe (see bane). In addition to the extra damage from the bane ability (see above), a slaying weapon deals an extra 1d10 points of damage on a successful critical hit. If the weapon’s critical multiplier is x3, add an extra 2d10 points of damage instead, and if the multiplier is x4, add an extra 3d10 points of damage.
Craft Magic Arms and Armor, summon monster V; Cost +2 bonus