Sanctuary Fighting back the darkness with style.

John Constantine is a cheeky, sarcastic, cynical bastard. He is the main character of DC's Vertigo comic Hellblazer, and the film Constantine (played by Keanu Reeves.) He is British, blond, chain-smokes, and has managed to piss off the Devil himself.
John is a mage who has made it his mission to send demons back to hell, and seems to constantly be cleaning up other people's messes.
He has had to think fast to keep his own soul out of Lucifer's clutches, and he's escaped his fate often enough that Old Nick is pretty keen to get his claws into Constantine.