Your innate ability to shroud others in darkness is further empowered.

Prerequisites: Fiendish Darkness, darkness spell-like ability, caster level 3rd, tiefling.

Benefit: You gain a +2 bonus to your effective caster level when using your darkness spell-like ability. In addition, whenever you cast a spell with the [evil] descriptor that targets another creature, you can spend a swift action to apply the effects of your darkness spell-like ability to the spell cast, with the darkness effect centered on the spell’s target. Using the darkness spell-like ability in this way expends all three uses of it for the day, and it cannot be used if fewer than three uses of it remain for that day.