The demon world I designed

The reborn Chen Qing became a hard-working student in ancient times. After living in poverty for ten years, he finally got a title on the gold medal list. He thought that he would become a scholar from now on. Chen Qing, who married Bai Fumei and reached the pinnacle of his life, was suddenly involved in a strange fantasy event.
It was also at that time that he discovered that this world was not simple. There were man-eating monsters, demons that bewitched people's hearts, and immortals who were said to be immortal but extremely weird!
What makes him even more incredible is that... these deadly things seem to be... designed by himself! ! !