Energy drain

Energy drain is a necromancy spell that severely weakens a target.

Effect
This spell functions in the same manner as enervation, except the creature struck gains 2d4 negative levels, and the negative levels last longer.

Twenty-four hours after gaining any negative levels, the subject must make a Fortitude saving throw (using the spell DC in this case) for each negative level. If the save succeeds, that negative level is negated. If it fails, the negative level goes away, but one of the subject’s character levels has been permanently drained.

If the ray strikes an undead creature, that creature gains 2d4+5 temporary hit points.