7th Demon Prince Jilbagias' Chronicle of Demon Kingdom Toppling - Chapter 63: Sincerity of The Dark Dragon

When the system warned the world that it was coming a week in advance, Alex couldn’t have been more excited. In college for a degree he didn’t care about to get a job he didn’t want, the promise of a world where magic and challenge awaited — even at the potential cost of death — was the best news he possibly could have imagined. Alex was ready for a new life. He ready for his only friend to shove him through a portal into hell the moment the apocalypse started. Instead of getting to punt rabbits and farm wolves, Alex finds himself stranded in a warped world where even the bugs are stronger than he is. Even with a summoner class that gains the powers of its monsters, most people would have died. Alex didn’t get the memo. He might have liked challenge a little bit too much. Where others saw certain death, he found something else. Opportunity.

Question, there is a beauty under the starry sky, her black hair looks like eternal night, her bright eyes shine like stars, her powerful magic power makes the world tremble, and her peerless beauty makes all living beings surrender, who is this beauty?

“That’s right, it’s me, the Witch King, Dorothy”

ps: The real name is “Otaku Witch”, a slow-fire setting text, too watery to enter! Don’t like water! Don’t like water!

- Description from novelbuddy

Shao Di Yu, an orphan, is adopted as a result of of a murder case involving the deaths of his entire family. Because of some painful experiences, he refuses to speak. However, he has sharp insight; moreover, he becomes under the care of a pair of twin brothers in the police force, who also have a child currently in university. Yu Yin possesses yin-yang eyes, which allow him to see things ordinary people cannot. The two brothers happen to complement each other, and together they investigate various inconceivable incidents.

This is a cliché story about two young people saving the world.