Nano Mashin - Chapter 24: The second test (2)

Karnak, a human born as an illegitimate child in a fallen aristocratic family, rose to the transcendent rank and became the Death King. Even god couldn’t contend with him.However, after becoming transcendent, he missed his human emotions, such as satisfaction and other things.So, with his oldest friend and second-in-command, who shared his belief, he decided to return in time with Barros and start over.However, something seemed wrong with this timeline.Now is the beginning of the new adventure of the Death King Karnak.

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

This is the tale of an earthling, who transmigrated as a dying third-rate god but somehow rose through the ranks, gaining followers and eventually causing the Fourth Great Apocalypse.