Godsbane was the sword that belonged to Cyric. Prior to his imprisonment, he shattered the sword in revenge against Mask who inhabited the sword and attempted to hide from Cyric.
Godsbane needed to consume the energy of souls to survive. "She" sucked all the blood from her victims, giving her a blood-red hue. When starved for a long time, she gradually faded to white. Before she came into the grasp of Cyric, Godsbane had driven all of her previous wielders mad, forcing them to sustain her by killing victims. Eventually, the blade would be stolen by another, and the former wielder's thoughts would always be focused on recovering it. They would never sleep until they'd recovered the blade or died trying.