In the MCU/Marvel with the Omnitrix/Ultimatrix - Chapter 20: Interview and family dinner

This book is also known as ’Because I Spoiled My Wife Too Much, I Was Forced to Become an Invincible Antagonist.’ Gu Lan transcended into a fantasy novel as a supporting scholar. He even gained a beautiful and delicate wife. He had initially planned to live quietly, avoiding all kinds of trouble based on the original plot, and spending his life peacefully with his beloved wife. But he happened to acquire the ’Read and Copy Books System’! As long as he read and copied books, he could extract cultivation, becoming a saint and even a deity! Due to being overly invincible, Gu Lan casually crushed major antagonists when he ventured outside. Sons and daughters of fortune were eager to acknowledge him! As his strength skyrocketed, his career went surprisingly smoothly as well. One day, Gu Lan, the top scholar from the high school examination, entered the palace and saw a stunning empress behind the curtain, who looked very familiar! “Babe?” “Darling, don’t you not recognize me when I put on the dragon robe?” “...” From that day on, the whole world knew about this extraordinary couple. The original male protagonist: “He’s already a Heavenly Emperor, and I’m just at the third stage of martial power. How am I going to compete?”

Dual cultivation isn't a choice; it's a necessity.

After being struck by a truck like most lucky protagonists (or unlucky ones), Vaan found himself transmigrated into the body of an orphan in the world of witches and demons.

However, they didn't always exist.

Demons terrorized the world ever since the Gehenna Realm descended over 300 years ago. but along with them, came mana, giving birth to witches to combat these demons.

Since then, the world of men was dominated by witches, establishing the seven witch kingdoms, which safeguards at the forefront of the demon invasion.

In order to survive in the matriarchal society of the witch kingdoms, Vaan, like all other men who cannot use magic, had to learn how to service the witches to survive.

Nevertheless, it did not come without its own benefits.

Years of research have led the world to the discovery of intimacy between men and women could increase the witches' mana absorption.

But at the same time, men could absorb some of this mana to improve their physique and lifespan.

Thus, since then, an intricate relationship was formed between men and witches in the red-light districts. Love became casual, and dual cultivation is common.

As a prodigy in the art of pleasing women, Vaan lived a smooth two years since his transmigration as an orphan.

However, everything came crashing down in a heartbeat one day when his life was nearly taken, and Lady Eniwse whom he served went berserk.

Even so, that was not the end.

With the awakening of the Witch Hunter System, watch how Vaan takes on the world and becomes the lord of witches.

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Note: Contains lemons.
Hunting witches does not necessarily imply killing witches if you know what I mean ( ͡° ͜ʖ ͡°)

As the grandmaster who founded demonic cultivation, Wei WuXian roamed the world in his wanton ways, hated by millions for the chaos he created. In the end, he was backstabbed by his dearest shidi and killed by powerful clans that combined to overpower him.

He incarnates into the body of a lunatic who was abandoned by his clan and is later, unwillingly, taken away by a famous cultivator among the sects—Lan WangJi, his archenemy.

This marks the start of a thrilling yet hilarious journey of attacking monsters, solving mysteries, and raising children. From the mutual flirtation along the way, Wei WuXian slowly realizes that Lan WangJi, a seemingly haughty and indifferent poker-face, holds more feelings for Wei WuXian than he is letting on…

- Description from Novelupdates