The Witchblade is an ancient artefact of tremendous power, wielded each generation by a strong-willed female of its choosing. The 'blade itself is sentient, and can vary its shape to create armour or blades, can create bolts of fire or electricity, and forms a telepathic link with its bearer and past bearers.
The 'blade appears to be controlled by three gems set into a bio-organic substrate, although the red gem was damaged and is currently missing; this seems to have had the effect of making the Witchblade even less controllable, its moods swinging between extreme violence and docility.
Sara Pezzini is the Witchblade's current host.