From the look of the blade, it was a black chipped thing resembling a copy of Maliketh's blade. Death knew what he wanted to do with it, so she didn't try to make it original.
This is a amazing story I hope the story continues up until he becomes a God if he does become one anyway you never know the story. Hope he does though.
Ch 80 Chapter 80
Percy Jackson: Son of Hades - Prince of the Underworld