Improved Energy Drain
(Libris Mortis: The Book of the Dead, page 27, DnD 3.5)
[Monster]
You draw extra power from your energy-drained victims.
Prerequisite
CHA 15, energy drain supernatural ability
Benefit
Whenever you bestow a negative level upon a creature, you gain a +1 bonus on skill checks, ability checks, attack rolls, and saving throws for 1 hour.