Skeleton Knight, in Another World - Chapter 5Volume 6 -

When a person dies, they either die light as a feather (aka unimportant) or heavy as Mt. Tai (aka very important).

King of the silver screen, Fiennes Tang, passed away after years of fighting heart disease. He woke up to find himself in the body of an outdated idol male starlet. Since the heavens had given him a new opportunity, he decided to enjoy life to the fullest and reach the summit of the entertainment industry once again.

- Description from Novelupdates

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 ͡°)

The clock struck midnight when Ruelle heard the echo of footsteps. She tensed, the fine hairs on the back of her neck standing on end in the cool night air.“You shouldn't be here,” Ruelle whispered, her voice a breathless murmur. The silhouette finally came to stand under the moonlight, his dark red eyes watching her and his inky black hair ruffling.“Shouldn't I?” His voice was a dark caress, and she stood there captivated by the danger he exuded like perfume.“I haven’t seen you for the last two days,” his tone low. His hand reached out, fingers brushing against the silk of her nightgown, tracing the trembling outline of her collarbone. “Tell me, were you avoiding me, or perhaps... entertaining other offers?”Ruelle’s heart raced, her breaths shallow. She declared, “I don't belong to anyone.”“A bold claim,“ he murmured, his breath a tantalising chill against her skin as he leaned in. ”Yet here you are, pulse racing, your body tensed as if in anticipation of my touch.”His fingers gripped her chin, tilting her face towards his. The moonlight caught his eyes, revealing a glint of predatory intent. “Or must I remind you whose touch you truly crave?”