Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Side Story: Sisters

It’s a story about a man who got transported into a novel and possessed a slum boy. He met a noble girl and served her as a butler for 13 Years. Now the girl has already fallen from her noble life and lives in an abandoned mansion with paralyzed legs. Why did she become like that? Of course because she is the villainess in the novel.

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

As a graduate with a double degree from a prestigious university, Feng Jun somehow remains unemployed after graduation. He struggles in the city, but he can’t let go of his pride. It’s easy to imagine the difficult situation he finds himself in.However, everything change after one day—he and his phone are struck by lightning and he suddenly discovers that he can turn into ‘DATA’ and enter the applications in his phone.What can he do afterwards? Harvest plants in QQ farm? See other people’s hidden photos and posts on WeChat? Become a character in a mobile game? Use your imagination! Wait a minute, change the deposited amount in his mobile banking app? Stop there, that can’t be changed at will!With absolutely more adventures than the ones listed above, he also realizes that he can even freely enter Eastern cultivation novels.Let’s follow Feng Jun and embark on a wonderful journey of immortal cultivation!

Master said, the woman I held in my hands, I must protect for the rest of my life.

Master said, it’s hard to cultivate as a Demon, and once you enter the Demon Dao, you should never look back.

Master said, Heaven is a Circle and the Earth is a Square; that Circle represents (is) consummate perfection, and that Square represents (is) the edges and corners of one’s Heart, it’s a rebellion against Fate, a Disobedience to Heaven.

My master is named Ning Fan, he’s not a person, he’s merely a Butterfly who has entered Demonhood. He was searching for someone. No one knew who he was searching for. No one knew how long he would search for…

- Description from novelupdates