Ramuz
Ramuz was an NPC, associated with the Shadowlords. He was noted for his ruthlessness, and murdered an entire family in Moonglow solely to use their house to monitor the invasion of that city by Minax's Orcs.
He was captured by players during an EM Event. After roughly 3 weeks of captivity (it is unspecified if he was tortured or not), he revealed information that led to a direct confrontation between the players and Minax.
As far as anyone knows, Ramuz is still somewhere in the dungeon of Lord British's castle, even as his masters launched a direct, bitter, prolonged assault on Britannia (see War of Shadows).