|Species||Unknown; possibly Demon|
- "I'm getting stronger every day. And when the time is right, I will rise! And then, I'm going to drain the world dry! I'm going to lap up every drop of hope and love and feel it run down my chin! I'm going to turn men into beasts and ruin their women and spit poison into their children, I'm going to scorch the earth with proper, Old Testament despair and teach them that the gods are there to be feared, and everything you love will die and everything you're scared of will come true!!"
- ―The Devil in his Captain Hatch form to Patsy.[src]
The Devil is a powerful, evil supernatural being, who feeds on the energy produced by conflict between Vampires and Werewolves. It is unknown whether he is the biblical fallen angel Lucifer, or another entity. According to Lady Catherine, if and when the Devil grows strong enough the Apocalypse will start.
According to Regus, presumably in ancient times, the Devil turned two Asian brothers into the first Vampires as part of a pact between the brothers and the Devil (the Devil would grant the two brothers eternal life, and in exchange the brothers would drink blood). (Eve of the War)
In the 1910s, the Devil influenced two Vampire and Werewolf clans, to spark a war between them from which to feed. In 1918, Hal Yorke, Lady Catherine and Emil Parsons summoned the Devil and trapped him in the body of Captain Hatch, in order to be able to kill the Devil before he could grow strong enough for the Apocalypse to start. However, as the trinity binding the Devil was improper due to an error on Hal's part, the Devil was merely weakened and trapped in Hatch's body, and killed Emil, Catherine and a Vampire and escaped. The Devil was apparently still trapped in Captain Hatch in 2013 following the ritual summoning of 1918, and was staying at the Barry Grand Hotel. (The Trinity)
After Hal and Tom McNair came to the Hotel, the Devil hoped to get the two to begin fighting so that he could begin to regain enough strength to reduce the earth to ruin, and at one point manipulated Hal and Tom into fighting each other. However, the Devil also saw Alex Millar as a threat to the former's goal of regaining his strength from Hal and Tom's fighting, and so sent the Men with Sticks and Rope to take Alex to the Other Side; but the Men failed. The Devil also manipulated Patsy into giving Hal and Tom their jobs at the Hotel back after the two were temporarily fired, and then had Patsy apparently kill herself. (Sticks and Rope)
Little is known of the Devil's personality prior to being bound in mortal form though it was quite cunning; able to manipulate and intensify the conflict between Werewolves and Vampires. When bound it appeared to lack the ability to speak; expressing it self with savage snarls when it realised it had been tricked. It was unfazed by the supernaturals' plot to kill it and despite being weakened killed the majority of the conspirators with its powers all the while laughing as it did it.
According to Hal, the Devil has a sense of humor and likes to remind Vampires that their souls belong to him, by removing Vampires' image from mirrors, film and camera.
The Devil lacks a body of its own and when manifesting it takes the form of a black vapor. When inside a vessel it contorts the body while "adjusting" to the host. When expressing rage or excitement or using its abilities, the host's irises glow red and the rest of the eyes turn jet black.
- Possession - The Devil lacks a form of his own, and thus requires a vessel when on the physical plane. He cannot possess supernaturals and must therefore possess the nearest human he can find.
- Longevity - The Devil's current vessel, Captain Hatch, has survived for 95 years since the Devil was trapped in Hatch's body.
- Mind control - The Devil is able to manipulate mortals (and possibly other beings) through the use of whispers, and also commands once an individual is under his control.
- Killing force - The Devil is capable of killing a medium sized group of supernaturals by sheer force of will; causing Vampires and Werewolves to choke to death and causing a Ghost to disperse.
- Biokenisis - The Devil can cause people's blood pressure to increase massively, to the point of heavy bleeding from the eyes, nose and mouth.
- Rot - The Devil once caused a vase of flowers to wither and die just by passing by them.
- Reality warping - The Devil could manipulate buildings' interiors so that whenever anyone entered an exit from a room, they would come out back in the room through another entrance.
- Door opening - The Devil can open Doors to the spirit world.
- Control over the Men with Sticks and Rope - The Devil can apparently control the Men with Sticks and Rope and even allow them to manifest on the physical plane in their natural form.