Enervation

This spell temporarily suppresses the subject's life force. The necromancer points his finger and utters the incantation, releasing a black bolt of crackling energy. The subject must roll a saving throw vs. spell, adjusted for Dexterity, to avoid the bolt. Success means the spell has no effect. Failure means the subject is treated exactly as if he had been drained of energy levels by a wight, one level for every four levels of the caster. Hit Dice, spells, and other character details dependent on level are lost or reduced. Those drained to 0th level must make a system shock check to survive and are helpless until the spell expires. The spell effect eventually wears off, either after 1d4 hours plus one hour per caster level, or after six hours of complete and undisturbed rest. Level abilities are regained, but lost spells must be rememorized. Undead are immune to this spell.

[Player's Handbook]

School: Necromancy
Level: 4
Rarity: Common

Range: 10 yards/level
Components: V, S
Duration: 1d4 hours + 1 hour/level
Casting Time: 4
Area of Effect: 1 creature
Saving Throw: Negates