When cast, this spell transformed the caster's forearm and hands into deadly claws, blacker than the darkness night. This was done by drawing shadow material from the Plane of Shadow. The caster could lengthen the claws up to 6 ft (1.8 m) in length. The claws were as sharp as swords, and when a target was struck, they experienced extreme cold.
During the course of the spell, the caster was only able to cast spells which required only a verbal component to cast. The caster was also unable to handle items with their hands, and any magical equipment or items on their hands were rendered useless until the spell expired.