Jimmy A. Aleister

"Be careful. It doesn't take much to get someone killed."

An elderly gentleman who is Twilight’s second-in-command and runs their operations division. His nature is always calm and exceedingly polite. He and Helsing have apparently crossed paths before.

Spoiler

His true name is James Moriarty, a criminal mastermind and arch-rival of Sherlock Holmes, who has been going under a false identity throughout the story.