He Possessed the Body of the Person Who Killed Him

A low-ranking cultivator obtains a manual of peerless martial arts in a secret realm.

Someone hears the news and comes to seize the treasure, killing him with a single sword strike.

When he opens his eyes again, he finds himself holding a sword, with his own corpse lying before him.

He has become the person who killed him.

Theme: Life goes on, generation after generation