Chosen of Evil

(Elder Evils, page 12, DnD 3.5)

[Vile]

Your naked devotion to wickedness causes dark powers to take an interest in your well-being.

Prerequisite

CON 13, Any other vile feat

Benefit

As an immediate action, you can take 1 point of Constitution damage to gain an insight bonus equal to the number of vile feats you have, including this one. Until the end of your next turn, you can apply this bonus on one attack roll, saving throw, ability check, or skill check. Make this decision before determining the result of the roll.