Versatile Mage: Killing God and Turning into Demon

(Guan Zhongzong, great mage, don't torture your heart, don't feel aggrieved) When I wake up, the world has changed drastically. The mysterious Kunlun Mountains, the dark ancient imperial tombs, the dilapidated tombs of the pharaohs, the advent of a prosperous age of magic, the intensification of demon attacks, internal and external troubles, how the ending has changed, please allow the author to think carefully.