Others Have Practiced Hard for Hundreds of Years, but You Became a God in One Second by Slaying Demons?

On the first day of time travel, someone stabbed me in the chest. Behind him is the brother who sold his life, in front of him is the ape demon who wants to eat his flesh, and in his arms lies a girl who was sent to be the demon's concubine. His predecessor was a black-hearted policeman who gave people away to the devil, and he deserved to die. But he, Lin Yuan, didn't deserve to die. In my previous life, I died suddenly in a rental house and no one collected the body. It was so difficult to live again. Why should I use it as a tonic for an animal? [Should I spend my longevity to deduce martial arts? Thirty-six years of life, all poured into the evil-killing sword technique in one breath! The sword suddenly appeared, and the ape demon split in half from head to toe, and its internal organs spilled all over the floor. One knife. Just one knife. But the price is - he only has thirty-one days left to live. Can slaying demons absorb demon life essence? Can you deduce martial arts but can't save your own life? Then kill! Go to death!