The Great Core's Paradox - Chapter 51: First Contact

Haruto Hayase was a normal high school boy in his third year, living a quiet life until his younger sister, Haruka Hayase, joined the same school. Haruka’s beauty and charm made her the center of attention, quickly becoming the school’s prima donna. But when a notorious gang leader set his sights on her, he did everything in his power to protect her—only to fail tragically. Haruka was brutally assaulted and tortured, and Haruto himself suffered an agonizing death. However, in a twist of fate, Haruto is given a second chance, waking up a year before the events that shattered his life. Armed with the mysterious ‘Debauchery System Slave’, he vows to exact revenge on those responsible. This time, he will use his newfound powers of the system and charm to seduce the loved ones of his enemies. From their mothers, sisters, and lovers to their closest friends, Haruto will make them his. His enemies will suffer as he steals what they hold dearest, ensuring their downfall in the most devastating way possible.

A world full of magic and wonders, where dragons stand for metals, sprites stand for farming, knights cultivate qi, mysterious wizards dwell. In this world, a man who had transmigrated into the body of a baron, follows the prompts of mysterious symbols to change his destiny.

- Description from Novelupdates

This is a world where science and magic coexist.

Some people here seek powerful magic, and some seek eternal truth.

A science tyrant who came from another world, started as a little librarian, with magic in his left hand and truth in his right, kicking the door of the new century with one kick.

Some people call him the forerunner of magic, some say he is the founder of science.

Some people describe him that way.

In the new century, Blair is a symbol of evil.

- Description from novelbuddy