MTL - The Life of a Villain Starting From Naruto - Chapter 124 so the answer is

A strange event happened in Blue Star, a large number of Blue Star people were affected by a mysterious force, and their souls temporarily traveled to another world.

It’s a dark, weird world

Not only are the prices extremely high, but there are also many evil spirits quietly appearing. At the same time, various forces are fighting with each other, and the people of the lower classes are suffering.

Yang Fangben, the attending physician of the mental hospital, also traveled through a strange incident.

Fortunately, he found that he had awakened a proficiency panel.

As long as you keep refreshing your proficiency, you can improve your own realm.

He grew up secretly, with corpses piled up under his feet, and he unknowingly embarked on a path of sagehood.

- Description from novelbuddy

At the end of the dark 40,000 years, the enemies in the Milky Way launched their final offensive. When the end of the Era comes, the eternal war will come to an end. The human empire has now reached its destined final moment.

But the gear of fate does not end. The fate of the Milky Way will be determined by him and them as it was ten thousand years ago. What will happen at the end of this dark 40,000 years?

- Description from novelbuddy

Upon opening his eyes, there before him was a bridal chamber adorned with red candles and windows.A bride dressed in a phoenix coronet and robes of rank sat upright on the nuptial bed, her face covered by a red bridal veil.Zhao Rong rubbed his sleepy eyes, “Have I become a groom? Oh, and a junior one at that.”Understood.His facial expression brewed for a moment before he twisted his mouth into a smile, “Wait a second...”Huh, something's amiss.The bride is my childhood sweetheart who also harbored a crush on me?Oh, then that's alright.This is very fitting.Zhao Rong stepped forward, happily lifting the red bridal veil, “Hey hey, my lady, where are you running off to?”-------------In the great era of contention, the tide of the times surged forth, and Confucian Scholar Zhao Rong bravely faced it head-on. Not only did he seek to catch up to the footsteps of his childhood sweetheart turned Sword Immortal Lady, but he also wished to witness firsthand the dispute that engulfed more than half of the Cultivation World, the strife among the various schools of thought...—————[Slow-burn], [Non-cliché], [Non-level-up], [Romance plot], [Sweet without the angst]This book is also known as “I Have a Fox Fairy Wife”, “Rebirth: I Deliver Parcels in the Otherworld”, “Zhao Ziyu, The Smirking Scholar” “I Really Don't Want to Be a Kept Man”...

A teenager who unexpectedly gets transported to the modern world from ‘the world of the immortals’ . He finds himself in the body of an ordinary guy. He wants to go back to his world and for that, he will have to practice to get stronger and investigate the reason why and how he crossed through to this world.