Devil, Stop Pretending and Save the World.

System text + counter-routine + dual systems and dual protagonists Gu Changsheng died suddenly after staying up late and transformed into the Doomsday Demon Lord, a world-destroying villain who was about to massacre the city. Because of a system failure, he was recruited as a son-in-law by Chu Yuehan, the daughter of the city lord. But he didn't expect that his wife was an ancient evil spirit from more than 10,000 years ago. One relies on modern medicine to do good deeds, and the other relies on ancient magic skills to play matchmaking. The two "villains" kidnapped by the system originally just wanted to survive, but they found that the power of merit and marriage were the keys to repair the rift in the world. But the city lord has laid a killing plan in the dark, the evil spirit of the Ten Thousand Ghost Cave is ready to stir up, and the original protagonist who was thrown into the abyss is about to return... The devil who once wanted to destroy the world is now forced to shoulder the burden of saving the world.