Demi-Gods and Semi-Devils: From Lovesick Zhong Wanchou to the Demon Venerable of Ten Thousand Calamities

A modern-day patient with a terminal illness died and was reborn as Zhong Wanchou in the world of Demi-Gods and Semi-Devils. Given another life, he refuses to repeat the original Zhong Wanchou's mistakes and resolves to change his image and stop being a simp.

He steals the protagonist's opportunities and practices the strongest martial arts. How does he end up becoming a great villain along the way?