Decapitating Carving Knife
The blade transforms into a a massive broadsword shaped like a giant butcher knife, It has a circle cut out of the top and the semicircle near the handle, which, seems to fit the sword's purpose of decapitation aptly, and gives something to wrap a back strap around. Its handle is detachable. The sword has the ability to reform itself using the iron harvested from its victims' blood. This regenerative process takes place almost instantly, and is capable of bringing the weapon back to its original perfect condition no matter how severe the damage is, from a simple chip or a nick to a completely missing half of the blade.