Superstar From Age 0 - Chapter 542:

You shall become king—

Ruling over all “serpents” in the world…

Become the man who bears the brunt of dragonkind’s fear and hatred.

A modern era when humanity is threatened by attacks from giant dragons flying from beyond the sky.

Controlling “leviathans”—serpentine spiritual beings created through magic—humanity is locked in a protracted war of resistance against the dragons.

Fortunately, there exist witches known as “magi”—battle maidens of salvation who formed covenants with “serpents” in order to combat dragons.

Nicknamed Hal, the young man called Haruga Haruomi makes his living through facilitating the covenants of these girls.

At the (partially coercive) request of his childhood friend Asya, one of Europe’s top witches, Hal returns to Tokyo New Town after an absence of three years.

Accompanied by the beautiful Asya whose appearance rivaled a fairy’s, Hal is running all over the place to secure his base of operations and taking care of matters related to school transfer when the elite dragon Soth suddenly attacks—!?

Life has been breathed into a brand new myth between dragons and dragonslayers.

A grand opening to the “birth” of a top-class battle epic!

The little handsome son-in-law passed through a world as waste material and the husband of a wealthy family. But because of his lacking aptitude, the wealthy family had driven him out. So he worked hard and found a more powerful family’s thighs to hold onto. Soon enough, he became the strongest son-in-law and husband in history.

In this world, it was impossible to practice martial arts. It was futile so he might as well take advantage of his wife’s thighs and maintain a comfortable and leisure lifestyle.

He’ll train his wife to become the strongest and best person in the world.

“Whoever dares to provoke me, let my wife kill you!”

- Description from Novelupdates

Xuanyuan was reborn into a strange new world where training to be a Xian was a cornerstone. There was however something ancient dwelling inside his body. He could now devour all of creation…

This is the journey of an ordinary boy and his transformation into the supreme being that reigns over all existence! Everywhere he went, he could not help but tie his fate with numerous women. It did not matter whether they were a goddess or a devil…

- Description from Novelupdates