Death of Dragon Teeth

He was killed by a female secretary in his previous life and was reborn into the body of a murderer who was about to be beheaded. However, this body contained the soul of a ten thousand year old dragon! Joined the Hunter Association and fought against four ancient ferocious beasts. He was framed, the dragon soul was pulled out, and he became a useless person... Nirvana and rebirth. What is the truth of this world? Why doesn't anyone believe it? I have a dragon tooth sword that can cut through the years and break the sky. How can one person's words convince everyone? How can the power of a dragon shake the heavens?