GREED: ALL FOR WHAT? - Chapter 2001: Chaos Spark.

Yang Qing never expected that he would travel to the fairy world, let alone that he would have a chance to travel back.

It’s just that after I came back, I found out that this world is not friendly to cultivation, and it’s a completely degenerated world, so what else can I do?

Part-time work is not allowed, so he can only rely on the rune technology of the fairy world and develop a little black technology to live his life, so his eyes are directly fixed on the moon above his head, where his dream begins!

- Description from novelbuddy

Shao Qing’s only regret in life is that she blindly fell in love with a worthless man. She gave up everything for him, but in exchange was run over by his conniving mistress when she was close to her delivery date. Fortunately, Heaven left her a way. Crimson rain fell from the sky, the end of the world arrived, she resurrected in the morgue and gave birth to a little monster. Turning into a half human, half zombie freak; her son neither human, nor monster; they have no other choice but to rely on zombies’ crystal nuclei to develop their special abilities and continue living. This debt, she’ll definitely repay that cheating couple!

- 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.

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

Sulí woke up from chaos without any memories, and without a system on her, simply living through each life cycle indifferently, guided by some mysterious force. Slowly, she realized that in every life, her identity was that of a supporting character with a bad ending...A wife discarded by her husband,The leading student led astray,An ordinary girl taken down by vanity,A childhood friend with toxic tendencies,Romances entangled with embroidered balls,The so-called phoenix men...After countless lifecycles, amassing immense merit and golden radiance, Sulí found out that things were far from being as simple as she thought.