Sadism

For every 10 points of damage the caster deals in a given round while under the effect of this spell, she gains a +1 luck bonus on attack rolls, saving throws, and skill checks in the next round.

Book of Vile Darkness 3.5
By Monte Cook

Enchantment [Evil]

Level: Assassin 3, Blackguard 3, Cleric 3, Pain 2, Sorcerer /Wizard 2
Components: V, S, M
Casting Time: 1 action
Range: Personal
Target: Caster
Duration: 1 round/level

The more damage the caster deals, the greater the luck bonus. It’s possible to get a luck bonus for multiple rounds if she deals damage in more than one round during the spell’s duration.

Material Component: A leather strap that has been soaked in human blood.