Invincible Demon King Mixed with Modern Times

He was a person who was unable to breathe due to a special constitution when he was born. Because he could not breathe, his parents thought he was stillborn and abandoned him in the mountains. Later, he was discovered by four old men living in seclusion in the mountains and rescued him back to their secluded place and named him Ren Tianqi. Eighteen years later, the four old men taught him everything they had learned throughout their lives and asked him to go down the mountain to live in modern society. When they left, the four masters did not give him any gold or silver. Instead, they gave him a bag of various tokens and certificates, and then kicked him down the mountain to start his modern life as an invincible devil. It was not very pleasant to pretend to be a pig and get slapped in the face.