I Became a Murderer in the Academy. - Chapter 76: A Peaceful Academy.

I was proposed to by the Final Boss.

Kai of the Sorcerer’s Tower is one of the last mages left, barely surviving in a world ruled by creatures of the dark — where the era of mages ended, and most of the lands got contaminated with dead mana. To save his world and fulfil his master’s last wish, he put himself through a forbidden ritual, risking his soul being ripped into pieces to make his way into the past. In an era with abundant mana — an era yet to enter the Golden Era of Magic. Things go wrong, of course, as they always do, and he finds himself thousands of years before the world fell to mana contamination — in the body of a young lord, Arzan. All is not well, though, as the young lord was murdered by someone right at the cusp of a beast wave threatening the territory, while larger threats loom on the horizon. There was a lot to do for Kai to regain his former strength in this time of primitive technology, but then again, he might just be able to change that.

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

Somehow, the protagonist Kim Jin possessed a rich pushover extra in a novel who was exploited by the villainess and then met their demise together.But there’s no way Kim Jin would let that happen! He immediately defeated the villainess and locked her away. After that, the only thing left was to steadily enjoy life in this world while investing and extracting profits using his knowledge.But why… the more he punished her, it seemed that the villainess he had captured began to cling to him too much?