Ghostly flaming apparition of a blade, slayer of spectres and all that is ethereal, wielded by its durable hilt inlaid in gold, silver, ivory and white pearls. It can turn the tide when fighting the intangible.
Deeping Steppes as named by Dargain the Gnomish adventurer who happened upon this place when attempting to find lost friends in a nearby series of caves and was swept in by the unexpected surge of an underground river, perhaps due to shifting of plates or erosion of a natural barrier. The cavern was sealed and unknown until being discovered by Dargain.
This is a region of the underdark where a series of very large plateaus occupy a huge underground cavern. The cavern is situated near a very common and sometimes treacherous underdark route know as The Underway (in my version of the world) which reaches from the Dales to Silverymoon regions in the Forgotten Realms.
A shape-shifter of some sort has taken up a post at the War College of an enemy realm, where he secretly picks off only the most promising officer cadets, arranging bizarre accidents that gradually debase the leadership of the hostile army. In the long run, this will improve his nation's chances when the inevitable conflict comes.
As a shape-shifter he can impersonate superiors and peers alike and send the target candidate to the cleverly-prepared site of his (or her?) execution. As long as he is successful, no-one will ever know about the deception--even necromancy will only implicate the one impersonated...