Your ability damage (or ability drain) special attack is more potent than normal.
Prerequisites: Cha 11, undead type, incorporeal subtype, supernatural ability to drain or damage an ability score.
Benefits: All variable, numeric effects of an empowered ability damage or ability drain special attack are increased by 50%. For example, an allip with this feat drains 1½ times the normal amount of Wisdom (roll 1d4 and multiply the result by 1½).
Source: Libris Mortis, page 26.