Versatile Mage: Slaying Gods to Become a Demon

(No harems, a great mage, no emotional anguish, no frustrating setbacks)

I woke up to find the world transformed. The mysterious Kunlun Mountains, the dark imperial tombs of ancient emperors, the ruined tombs of the pharaohs: an age of magic had arrived, and the demons’ attacks were growing fiercer. With troubles both within and without, how will things end? Please give the author some time to think it over.