Luke Castellan
Backbiter – a blade with one side of celestial bronze melded with tempered steel. The celestial bronze allows for the wounding of immortals and monsters, while the steel injures mortal. Backbiter is a foot longer than Anaklusmos, Percy's sword. Percy sensed a tragedy in the making of Backbiter. In the fourth book, it is revealed that the metal used for Backbiter came from Kronos's scythe. It is reforged into its original form for its master's rising.