Necrotic Skull Bomb(Champions of Ruin, p. 32)
Level: Cleric 5, Sorcerer 5, Wizard 5,
Components: V, S, M,
Casting Time: 1 swift action
Range: Close (25 ft. + 5 ft./2 levels)
Area: 20-ft.-radius spread
Saving Throw: Fortitude negates
Spell Resistance: Yes
You imbue a humanoid skull with negative energy and hurl it. The skull detonates on impact, releasing the negative energy contained within. All creatures in the spell's area, except for undead, gain 1d4 negative levels (see Energy Drain, page 308 of the Monster Manual, for details about negative levels).
Assuming a creature survives the effect of the spell, it regains lost levels after a number of hours equal to your caster level (maximum 15 hours). Usually, negative levels have a chance of draining a creature's levels, but the negative levels from necrotic skull bomb don't last long enough to do so.
An undead creature in the spell's area gains 1d4×5 temporary hit points for 1 hour.
Material Component: A humanoid skull.