Devastate undead

Devastate undead, also known as disrupt undead, was an arcane necromancy spell that sapped undead of their negative energy and destroyed them.

Effects
The spellcaster fired a beam at a number of undead targets and destroyed them in a manner similar to the power of a disruption weapon. A particularly resilient undead could resist or even be unaffected by the spell. A living being was immune to its effect.

The spell had a secondary effect of channeling negative energy from a damaged or destroyed undead back to the caster. This could either hurt the caster (if they were alive) or heal the caster (if they were undead themself).

Components
The spell required a disruption weapon of any kind as a focus.

History
The devastate undead spell was developed by the arch-lich Larloch. He used it to heal himself by sacrificing his undead servant creatures. He could even potentially use it to permanently boost his unlife force.