Like defilers of legend, you steal life force from your enemies, wracking them with pain and turning their bodies into lifeless ash in the process.

Daily   ✦     Arcane, Necrotic
Standard Action      Personal

Effect: You can use one of your at-will arcane attack powers as a free action. If the attack hits, one creature hit by the attack also takes ongoing 20 necrotic damage (save ends). Until the ongoing damage ends, the creature hit is considered to be your ally for the purpose of taking damage from arcane defiling. If the attack misses, this power is not expended.

Published in Dark Sun Campaign Setting, page(s) 64.