Stygian Iron

Stygian iron, like celsetial bronze, is a metal capable of killing monsters. However, Stygian iron is much rarer. Stygian iron, when being forged, is cooled in the river Styx in the underworld, producing a keen, indestructable blade. Because of it being cooled in the river Styx, many sons and daughters of Hades use it because of its availability in the underworld. One large difference between celestial bronze and Stygian iron is the way they kill monsters. Celestialbronze turns the monsters to dust, but Stygian iron sucks their essence away until they are killed. Another thing about Stygian iron is that it is usually consecrated with a swear upon the river Styx. One notable user of Stygian iron is Nico di Angelo, in the form of a short sword.