One Piece: King of the World - Chapter 412: Tesoro – Being the Minister of Finance Is Too Hard!

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

I got sucked into a novel full of villains and must tame them in order to survive!

Kazuki’s life was painfully average—just another cog in the nine-to-five grind. His only escape? Binge-reading novels and no-lifing video games.Then he woke up inside one of those novels.Armed with unstable morals, unhinged humor, and a penchant for pettiness, Kazuki is determined to survive, thrive, and maybe cause a little chaos along the way.The world has no idea what’s coming.

In a certain world, there was someone who excelled in magic combat, people called him 『Sage』. Seeking the strongest combat art, he devoted himself to research every magic and combat arts in existence. And the conclusion he arrived at was very cruel, 『My body is not fit for magic combat』. Yet he didn’t give up. He sealed his own soul with a magic art, and was reborn in a far-off future. And the magic theory in the completely changed world he saw there was of unbelievably low level.