She is the soul of the sword. She fell in love with her master and made herself irrecoverable.
Everyone who owns this sword seems to be unable to escape the fate of love...
The Feiyuan Sword, the weapon of the heavenly general Lingliang, has a soul due to absorbing the spiritual energy of heaven and earth for thousands of years. However, Feiyuan, the soul of the sword, fell in love with Lingliang. In order for Lingliang to be buried under the sky, her heart sutra turned into thousands of hearts of black iron for thousands of years.