Border of the Pure Land

"The Chronicles of Earth" record:
In December of 2534, Lu Bu'er, afflicted with a terminal illness, privately meddled with forbidden powers. By studying the life structure of Specter Fiends and harnessing his own affliction, he created the ability to devour these Specter Fiends. This act abandoned the dignity inherent in being human, making him a target for execution by all!
In August of 2535, a tragedy befell the world, and the demon was crowned as a king.
In May of 2536, grave news: the rebellious monarch, Lu Bu'er, was approaching the city of the Lord!
In July of 2537, we welcome with reverence the arrival of the great fourth generation Sacred Monarch to his loyal City of the Lord!
【Not a post-apocalyptic wasteland novel】