I Signed at the Execution Ground for Fifteen Years and Was Invincible Since Birth.

I have been an executioner in the execution ground for fifteen years. I thought I would only behead tens of millions of people in my life and do nothing. Until that day, the Ministry of Punishment escorted a girl in white. She raised her head and smiled, and the ghost-headed knife in my hand broke. "Sir," she said softly, "this sword cannot kill me." The supervisor screamed in horror, but I suddenly realized that there really are immortals in this world. That night I opened the ancestral sword manual, and on the first page it read: "Nine hundred years of killing immortals, you should call it an end." It turns out that what I sign in to every day is not the execution ground, but... The immortal's cemetery.