Corvin the Caller is a mysterious, raspy-voiced character in Kozerlen. He was originally going to be played by the Dozerfleet founder.
Exactly who he really is and what he wants remain a mystery to all but himself. At one point in the story, there were plans that he'd be exposed by Jessie after a fight. She'd actually get to compel him to switch sides in her war, supporting her.
Inspired by the Mouth of Sauron character in Return of the King, the Dozerfleet founder wanted to have Cassie's Jessie Morcin character have taunts and clues dropped randomly by a figure who was mysterious even to the audience. This would be achieved by having a character who was never shown above the lower half of his nose. He was, in practice, to be something somewhere between Mouth of Sauron and Rorschach.
When the pitch for Kozerlen was abandoned in favor of Blood Over Water, Corvin was replaced with the character of George Lawence. While George is much more clearly and unambiguously evil and hammy, his voice effects are toned down from Corvin's considerably.
Also, much of Corvin's intelligence was toned down; reducing George to a not-real-bright, psychotic thug. While Corvin would have used technique multiple times, George only uses it once - at the end of Part 2.