This sword has special powers and can be used together with the Ancient Helmet.
Use
It will cast lightning and turn pigs into zombie pigmen, creepers into charged creepers, and set everything on fire. Use with care!
Obviously, because of the lightning effects, using this sword on pigs and creepers is not recommended. When hitting a zombie pigman with the ancient sword, it will turn into a friendly, nonmoving large zombie pigman.
Recipe
It is created after putting a Ancient broken sword in the Archeology Workbench, and placing relics in the bottom slot, at least 10, to build it.