Empower Supernatural Ability( Tome of Magic, p. 73)
You can use a supernatural ability with greater effect than normal.
6 HD, supernatural ability,
Once per day, you can empower a supernatural ability. When you use an empowered supernatural ability, all variable, numeric effects of the supernatural ability are increased by one-half. An empowered supernatural ability deals half again as much damage as normal, cures half again as many hit points, affects half again as many targets, and so on as appropriate. Saving throws and opposed rolls (such as the one made when you cast dispel magic) and supernatural abilities without random variables are not affected. You must declare use of this feat before you use the ability. A continuous use ability (such as a gaze attack) can be empowered for only 1 round. Empowering a supernatural ability does not require a separate action. An empowered supernatural ability cannot be maximized.
This feat can be taken multiple times. Each time it is taken, you can empower a supernatural ability one additional time per day. You cannot empower a particular use of a supernatural ability more than once.