10 nen goshi no HikiNiito o Yamete Gaishutsushitara Jitaku goto Isekai ni Ten'ishiteta - Chapter 9, Idle talk 4 [9-15] Certain two adventurers, obtaining help

Ye Qiu traveled to the Great Wilderness World and obtained the ten thousand-fold return system.

By teaching or gifting the same thing to the apprentice, you can get a high multiplier crit return.

“Ding, you give your disciple a Marrow Cleansing Pill, trigger a thousand-fold crit, and get a Divine Marrow Pill.”

“Ding, you passed ten years of kung fu to your disciples, triggered a hundred times of critical strikes, and obtained thousand years of kung fu.”

“Ding, you gave your disciple the Zixia Sword, a top-grade treasure, which will trigger ten thousand times the crit and get the Immortal Sword Yunxiao.”

All the disciples: “Master is too generous. He never hides his secrets from his disciples, and he gives everything away.”

- Description from novelbuddy

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 ͡°)

Vahn decides to spend a bit of time with Sarina in the Actualized World of Dragon Ball.

“From today onwards you are no longer my son. Get out” Being born into a noble family that is aiming to become the ‘strongest’, at his aptitude ceremony held on his 12th birthday it was discovered that Igni could only use fireballs. Igni who can only use beginner level magic was kicked out of his house.

With no where to go and without much magical ability, Igni is scraping by through life. However, one day he has miraculous reunion. “What? Is that Igni there?” “Gr-grandpa!?” It was a reunion with his grandfather, the man who was once called the strongest [Kyokuten] but was banished from his noble family because of his excessive womanizing…! “Grandpa! You said strong men are popular, but I can’t be strong!!” “Igni, listen carefully. Strong men are popular but, hard-working men are even more popular!!” “Grandpa! I’ll try my best!!!” Igni whose parents who banished Igni from the house, didn’t yet know of his obsession with being popular under the guidance of the strongest [Kyokuten] magician…!

“Igni that magic!” “This? It’s a fireball” “With this you can aim for [Kyokuten]! Come back here!!” “Nobility isn’t popular” “What are you saying?” This is a story where a young magician becomes the strongest by honing his skills all in order to become popular.