This spectral light is also known as the Nail of Hades. Often seen hovering above the corpses of the newly dead, the ancient Greeks believed the light was responsible for the harvesting of souls. It is unlikely that any mortal can triumph against a weapon with such strong associations to death.
Orcus Claw appears as a yellow color swap of Maleficus. While it has no immediate defining abilities, its power can be increased through Soul Charge and can maintain said state for a few seconds, but is vulnerable to Guard Breaks.