"Blood and souls for my Lord Arioch!"
- Elric of Melnibone
Duke Arioch appears in Michael Moorcock's fantasy works, including but not limited to the Elric series. Arioch is one of the Dukes of Hell and patron diety of Melnibone. He is a Chaos Lord. Along with Balan and Mulak, Arioch has immense power in Elric's part of the multiverse, though she/he is the weakest of the three "Sword Rulers" in Prince Corum Jhaelen's world. Like all of the Chaos Lords, Arioch's gender is uncertain as she/he can shift forms at will, although Elric always thinks of Arioch as a male.
My own theory is that in our own world, Arioch exists but is fallen from power. She/he is now Lord of Parking Spaces. I have found that invoking the name of Arioch is often helpful in finding that elusive perfect parking spot. I try not to promise him/her "blood and souls" however.