Under the Iron Sky
You draw forth the ebbing life force of a creature and use it to fuel your own power. Once per day, whenever this dagger is used to perform a coup de grace upon a living creature that has 0 or fewer hit points, you may activate the power of this dagger. The subject dies, and you gain 1d8 temporary hit points and a +2 enhancement bonus to Strength. Additionally, your effective caster level goes up by +1, improving spell effects dependent on caster level. This increase in effective caster level does not grant you access to more spells. These effects last for 10 minutes per HD of the subject creature.
In addition, whenever this dagger scores a critical hit, the target gains 1 taint.
This +1 dagger has a pommel carved from jet in the image of a leering devil. Its blade is made of the same material, but casts no reflections, despite its smooth surface.