Sergeant Edwards is a vampire working with Pellon Cross in the era of the Grendel Khan. They live in the Grendel's Palace casino.
Edwards is part of the plot to infiltrate the casino in the first place, dragging some clothes to a drop point in his dog form so another vampire, Hilary Raintree, can put them on and turn the casino employees into vampires. After that, the vampires take over the casino. They are eventually discovered and allowed to remain there, but are not allowed to leave. The entire place is put under guard by the Grendel Corps.
Edwards continues acting as an assistant to Cross, and is eventually given an important job: infiltrating the casino guards. The guards have to pass a test to see if they could bleed, which vampires couldn't do. However, Cross miraculously manages to start bleeding, and passes that trait on to his followers. In this way Edwards manages to become a guard.
While there, he becomes good friends with Charlie Adams. The two joke around, and Edwards even saves Adams from a bunch of vampires during a riot. However, Adams finds out that Edwards has been slowly turning the other guards into vampires. He's afraid of Edwards, but also feels betrayed, because he really thought they were friends. Edwards assures him that they are, and tells him he will love being a vampire. He then bites him on the neck.
Edwards presumably has the standard powers of a vampire in the world of Grendel, which include enhanced speed, strength, and durability, as well as the ability to turn into a dog, his totem. Vampires usually feel pain from the sun and water, and can be destroyed by fire, but Edwards and some of the other elite vampires trained to be able to endure the sun and water.