Okami Wa Nemuranai - Chapter 56.4

Rainer, an amateur arcanist and college student, sought to create a new spell far surpassing the magic of the few he inherited from his grandfather. Yet the interference of an unknown event during the casting of his spell led him to be thrown through space and time.

500 years ago, Chen Xi was devoured by a crack in the void and was transported into a cultivation world.

500 years later, he returned back to Earth after enduring through several hardships and discovered that only 5 years had gone by.

…

In the courtyard, beauty at the side, a candle flame wavering.

A gush of clear wind, half a full moon, the peach tree remains unchanging.

…

Wait, whose kid is this?! Why is she calling me papa? Gazing at the little girl in front of him with skin as pale as jade, Chen Xi froze.

…

　
Returning home from cultivation, starting as a stay-at-home dad.

In this life, not fighting to be a king nor claiming to be a tyrant, only praying to peacefully be a wife-pampering mad devil and a child-protecting daddy!

- Description from Novelupdates

After ten thousand years of cultivation, he could have achieved immortality. However, his lack of human experience led to his failure to attain immortality.Thus, he resolved to immerse himself in a century of human existence, seeking to enhance his journey toward immortality. What he didn’t anticipate, though, was that upon entering the human world, he would find himself cast as a son-in-law, facing disdain not only from his wife’s parents but also from his beautiful wife herself.Armed with a wealth of cultivation knowledge, how could he transform his drab human life?

Li Muyang had transmigrated, and the good news was that he had a system. The bad news was that this system could only be used to play games. Oh well, if it’s playing games, then so be it. It’s better than having nothing. In the game, he was powerful and mysterious, causing the extraordinary fairies to be shaken to their core. Since it’s just a game, there’s no problem in aiming for the full compendium route, right? It wasn’t until one day that the fairies from the game showed up at his door that Li Muyang was truly startled. What was supposed to be just a game, how did it become real? “So... listen to my excuse!” I was really just playing a game!!