Unholy Strike
(Complete Divine, page 90, DnD 3.5)
[Epic]
Your attacks deal great damage to good creatures.
Prerequisite
Smite good class feature, any evil alignment
Benefit
Any weapon you wield is treated as an unholy weapon (it deals +2d6 points of damage against creatures of good alignment). This ability doesn't stack with similar abilities (for instance, if the weapon is already an unholy weapon).