Herlock Sholmes

"Everything is interconnected at some level; mortality means very little in the grand scheme of things."

A private detective who came to London upon being summoned by Scotland Yard.
His excellent physical condition and superior intellect is without peer, and his ability to remain preternaturally calm at all times is legendary. He is also a constant thorn in the side of the protagonist and her allies, though he occasionally acts as their savior.
He makes it a point to keep his professional and private lives completely separate.

Spoiler

His real name is Sherlock Holmes, a famous detective, who has been pursuing the whereabouts of his arch-rival, James Moriarty.