The Demon Lord Returns to the City

The most exceptionally talented Demon Lord across the heavens fell while researching powerful demonic cultivation techniques, only to be reborn in his hometown billions of years in the past. Though he has returned to the city, he is no longer the sunny, upright young man he once was. How will this supremely evil Demon Lord, who looks down upon all living beings, regard the people of this world with cold indifference? And what methods will he use to create an endless purgatory?