Sister Di did die, and Xiao Gu made herself a big sword with her head.

The big sword is a half-man, half-demon made by human beings mixing the flesh and blood of demons.

There are performances in the animation. After Di Jie was cut off by Xiao Er, Xiao Gu looked for someone in the organization with Di Jie's head, and then met her contact, asking him to take himself back to the organization and turn himself into a big sword. Then Xiao Gu became a big sword.

Moreover, there are details in the animation to prove that Xiao Gu is Di Jie's own flesh and blood.

The former No.2 who gave Xiao Gu an arm asked Xiao Gu if he was Adijie, and Xiao Gu admitted it, so the man said that Xiao Gu was not even half man and half demon, and his strength was very weak.

Also, after the murder of No.4, the organization suspected that it belonged to Little Gu Gan, but Xiao Gu's contact said that the organization did not test whether the excellent lineage could be inherited. Even if Xiao Gu turned Di Jie's flesh into a big sword, it was not as powerful as Di Jie. ...