I Was Possessed By An Unknown Manga - Chapter 143: Persuade

A side story series featuring the girls of Kyoukai Senjou no Horizon.

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

After being betrayed and killed by his own brother, 17-year-old orphan Elias Black is given a second chance—by a mysterious, demonic entity. Reborn with the “Devil’s System,” he must now collect souls, gain abilities, and exact revenge on those who ruined him.But each power comes with a cost—and the devil never makes a deal without expecting something in return.As Elias grows stronger, unlocking deadly skills and forming uneasy alliances, he faces an even darker truth: his rebirth is part of a much bigger, bloodier plan.