Bane of Enemies

 
Prerequisite(s): 21+ level, Survival 24+ ranks, five or more favored enemies
 
Benefit: Any weapon the character wields against one of his or her favored enemies is treated as a bane weapon for that creature type (thus, its enhancement bonus is increased by +2 and it deals +2d6 points of damage). This ability doesn’t stack with similar abilities.
 
Source: Epic Level Handbook