{Traditional martial arts, fake invincibility, plot reversal, ancient dragon style, don't criticize if you don't like it}
A bodyguard who emerges from nowhere, a long sword that shines like a meteor
This invincible sword is used to seek revenge. This proud and arrogant swordsman will become the best escort in the world.
"I have a sword in my hand"
"I saw it"
"No, you didn't see it"
"Why?"
"Because you are a dead person, and dead people cannot see."
