Ankoku Kishi Monogatari ~Yuusha wo Taosu Tameni Maou ni Shoukansaremashita~ - Chapter 147.2: Sanshos Village

Criminal Psychologist, Su Xiao Pei, who was an leftover woman in her modern life, was informed by the God Of Marriage, Yue Lao, that her destined lover was in a car accident, his soul was sent to another world. Su Xiao Pei was ordered to bring back this strange man who was connected to her by the red string of fate. Otherwise, she will live the rest of her life in loneliness, with no one to support her.
But how does that man look? No idea.
What’s his personality like? No idea.
What does he do for a living? No idea.
Can she not go? Of course not.
Su Xiaopei, who believes in all things logical has run up against a serious wall this time.
The bottom line: This is a story about a modern female psychologist who has traveled back in time and an adorable warrior as they talk about love and solve crimes.

- Description from Novelupdates

Once upon a time, a boy was referred to as a “War Hero.”

In another world called Aletia, the boy who had saved the Lost Kingdom, conquered their neighbouring countries, and led to the rise of a grand empire decided to throw everything away, returning to the modern era at the cost of his memories.

As three years passed, the boy who was happily enjoying his daily life was once again called back to the other world.

However, what awaited him was the Aletia of 1000 years in the future.

As his past glories became a “myth,” the legend of the youth referred to as the, “Twin Black Hero King,” begins.

After 20 years of dedicating his life to opera ever since he had quit the performing arts high school, he had failed at an interview. Losing his motivations, Jo Yunjae depended on alcohol to live out his days until one day, he had been sent back 20 years in time, to the day before his high school admission.

The tens of thousands of universes have merged. The disintegration of spiritual force led to the momentous collapse of the great Cultivation World, a mighty era that had endured through millions of years of history. In the wake of the large-scale invasion of the Wilderness, the Avalon of Five Elements has become the practitioners’ last stand.