Bladebane

You impart a deadly quality to a single bladed weapon (any slashing weapon) for a short time. Bladebane confers the bane ability on the weapon touched, against a creature type of your choice.

Whenever a target makes an attack roll or a saving throw, within a minute after it was hit with this weapon, the target must roll a d4 and subtract the number rolled from the attack roll or saving throw.

The weapon also has a +2 bonus to attack rolls against the appropriate creature type, and it deals +2d6 points of bonus damage to those creatures.