This is the year 2xxx. After the disaster, everything has ushered in change and new life.
The order has subtly deviated from the original trajectory, and evolution has become the only way to reach the pinnacle of life.
The protagonist who traveled through time inexplicably possesses the ability to strengthen all things.
"My martial arts skills seem to be a little weak. Let's strengthen them..."
"This knife is a little rusty. Let's strengthen it..."
"This baby is pretty good. Let's make an enhanced version and call it Baby 2.0..."
Start with a heart attack, become a god and ancestor from now on, eat meat well...