A second chance
According to the legend, Dread Velsparge, Daemon Prince of the Myriad Hands, plunged into the Tarakhen Sea in a blaze of scarlet flame, throwing the whole world into ruin.
During certain years, people in Akgku claim to observe a green flame coming from the sea and erupting upward. It can be observed from a distance of two days’ journey or more. After burning for a considerable time, the flame disappears.
—Falklyde Wodinger, Haraconian scholar, in route to wondrous Udross and legendary Akgku.
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...