The Crazy Villain Regains His Sanity

A brief description of the manga The Crazy Villain Regains His Sanity:

The protagonist, Choi Joon-ho, who had lived his life as a ruthless villain, indulging in power and bloodshed, one day returned to the past when he was an unemployed shut-in. He decided to turn his life around and use his strength for good, facing various challenges and obstacles along the way.