Undeath's Bane

Kris Dagger (Simple Light Melee, 1d6 slashing, 18-20/x2)

Special Qualities

Magical: Undeath's Bane is a magical +1 weapon
Undead Vulnerability: When striking undead with this weapon, sneak attack and critical hit immunity do not apply.
Bypass Resistances: Attacks with this weapon ignore any DR inherent to undead creatures, and have no miss chance against incorporeal undead. DR and incorporeality not natural to an undead (such as a vampire with stoneskin or ghostform cast on it) are not bypassed by this quality.
Return to Death: If you have at least twice as many levels as a struck undead has HD (factoring in any turn resistance), it is destroyed outright. A confirmed critical hit destroys any undead with effective HD less than or equal to your level.