What does diamond yarn mean?

Diamond yarn generally refers to Han Lingsha.

Han Lingsha, the first heroine of the stand-alone game Legend of the Sword and the Chivalrous Man IV.

The girl who runs around with her family's fate claims to be a grave robber who travels thousands of miles alone. I am young, but I am very good at identifying the location of graves, cracking strange objects and geomantic omen.