The City of Terror - Chapter 642 - Blue Crab Demon King

I exist in the darkness, disappear under the bright light, and will eventually devour the sun and turn into the shadow of all things… Known by people as the indescribable terror of darkness; the king of shadows; the dark day; the existence of the shadow of the world , is still just a somewhat special high school student, facing a weird death game…

- Description from novelbuddy

A lecherous army special task force soldier from 21st-century Hong Kong is selected to travel back in time, choosing to go to the Chinese Warring States Period. Unfortunately, the time machine runs into an error during the experiment. With no foreseeable way to return to the present, he must use his combat skills and knowledge of history to thrive in his new life in the year 251 BC.

Inexplicably, she had crossed over to the end of the 1970s and was thrown into the mountains. Fortunately, she is rescued by a handsome soldier. Only later does she discover that Brother Soldier is actually the unlucky male supporting role of a historical novel. He was used and deceived by the heroine in various ways and finally dumped on the grounds of the progressive new era not supporting arranged marriage.

Damn, will such a good Brother Soldier will still end up like that in the future? If the heroine doesn’t want him, then step aside and let me have a go.

But how will we live in a time that lacks modern food and clothing? Hey, I bring something different, now I can guide this male lead to be well-fed and make the heroine get mad.

- Description from Novelupdates

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates