I Have the Alchemy Emperor in My Head - Chapter 34

While on a school field trip in the Czech Republic, Kang Hyuk happens to stumble into a shop called “Archmage.” To his disbelief, the shop is actually owned by an archmage… from another world! Forced to become the Archmage’s disciple, Kang Hyuk is punted into the Kallian Continent, where might and magic overwhelm and wyverns fly high in the sky…

In this world, people are either sword-wielding knights, magic-wielding mages, or spirit-wielding summoners. There hasn’t been anyone yet who can do all three… until now.

What would happen when someone from our world was suddenly reborn into the world of My Hero Academia with a Gacha System that rewards him with abilities, techniques, and skills from Jujutsu Kaisen? Grand epic fights and crazy shenanigans as he goes through the story to cause chaos and change the world to his liking.

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

Haruto Hayase was a normal high school boy in his third year, living a quiet life until his younger sister, Haruka Hayase, joined the same school. Haruka’s beauty and charm made her the center of attention, quickly becoming the school’s prima donna. But when a notorious gang leader set his sights on her, he did everything in his power to protect her—only to fail tragically. Haruka was brutally assaulted and tortured, and Haruto himself suffered an agonizing death. However, in a twist of fate, Haruto is given a second chance, waking up a year before the events that shattered his life. Armed with the mysterious ‘Debauchery System Slave’, he vows to exact revenge on those responsible. This time, he will use his newfound powers of the system and charm to seduce the loved ones of his enemies. From their mothers, sisters, and lovers to their closest friends, Haruto will make them his. His enemies will suffer as he steals what they hold dearest, ensuring their downfall in the most devastating way possible.