A Betrayal of Ravens
Lark was a prompt and charismatic emissary that secretly worked for Hextor, the God of Tyrrany and Chaos.
On the Prime Material Plane, he had neat blonde hair a shimmering grey cloak (which functioned as an entropic shield, and nourished Lark’s anarchic form that would not have been able to remain stable for very long).
Once the PCs retrieved The Key of Immeasurable Worth, he paid them each 100,000 gp, hinting at the nearly limitless hoard of wealth that the denizens of chaos had plundered over the centuries.
When the PCs came to battle Lark at Hextor’s doorstep, his true form emerged as a male Marilith, wielding the distinctive weapons patterned after Hextor’s own.