Nanomancer Reborn - I've Become A Snow Girl? - Chapter 1236: Shiro. C

After seeking pleasure in the nightclub and a night of romance, he discovered there’s a seed in his stomach;

She was originally the king of the dark mercenary world, killing, plundering, and looking down on the world; once reborn, she became a powerful family that shocked the continent, the “Ninth Young Master of Waste” of the Beiting family;

From then on, the elegance of the world, shake hands;

Belonging to ancient monsters, possessing a magical space, practicing heaven-defying skills, killing the sky, killing the gods, and doing whatever they want;

Cool and handsome, domineering and arrogant, leading the world to compete;

In this article, the male and female protagonists are double C, male strong + female strong, and the ending is one-on-one;

- Description from novelbuddy

Crossing to One Piece world, he became Roger’s younger brother.

The world had changed when the System arrived, alongside the Cataclysm that filled the world with monsters. The technology was gone, replaced by classes and skills that allowed the people to fight back. When Devon ended up as a Blacksmith, a class that didn’t grant Intelligence, he had to face the reality, that his old career that he loved - mathematical sociologist - was over. Instead, he had ended up as yet another discarded member of the production class, overshadowed by the existence of the System Shops to the point of total marginalization. But, what if all he needed was to reapply his scientific thinking to the System...