Don't Come to Wendy's Flower House - Chapter 89

As the number one pill alchemist of the immortal world, Mu Chen had always believed that it was because he had single-mindedly focused on concocting pills that led to him to neglect disciplining his disciple. Which in turn, caused his disciple to be led astray by the seduction of devil cultivation, leading to the three realms to fall to disaster. After his rebirth, Mu Chen resolved to properly teach his disciple, give him the very best resources, earnestly love him, carry him close to his heart, teach him by way of example, and didn’t let him grow corrupt.

Sure enough, his disciple became more and more “intimate”. Every day his disciple even crawled into his bed, rubbing against his chest and clinging to his thigh. It was just that his expression isn’t exactly quite right……

- Description from novelupdates

This is a world shrouded in darkness, and the pervasive black mist erodes all living beings.

Only fire can dispel the darkness and protect mankind.

But the firewood will eventually run out, the fire will eventually go out, and humanity will eventually perish.

until Rhodes came.

- Description from novelbuddy

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.

Qi Condensation. Foundation Establishment. Core Formation. In the current world, only these three realms are known to be achievable. Nascent Soul is but a legend and the realms above it lost to the the long river of time. The modern era is known as Cultivation Civilization, a balance of power and civility, excess and moderation. While cultivation remains a secret practice, it has long since exposed itself to the mundane world, quietly intertwined with each facet of society. While the world appears to be at peace, what lies underneath is a conflict between human, cultivator, and demon, brewing for ages and waiting to implode. Yet in the wake of humanity’s rapid industrialization, qi—and consequently cultivation—is dying.