One Piece - I Am A Different Luffy! - Chapter 441 - 440 - Mysterious Shichibukai 01.

The Swordmaster who has returned by chance to save the world!

In a peaceful, utopian Earth, a young man is born cursed by the will of the heavens. One day, he awakens… and uncovers the hidden world of the High Humans—the most powerful beings on the planet. His superpower? A rare support ability with healing powers… or is it? From that moment on, a healer who devours lives to grow stronger, just like the worst demons, is born. *** This is a story about superpowers in a distant future, where Earth hides unimaginable secrets. It’s also a journey across universes, filled with battles and discoveries. The protagonist isn’t a genius or a trained warrior. He’s just an ordinary man who faced dark times and watched his life be consumed by the abyss. But now, he has a chance to change everything. Step by step, he will learn why to fight—and how to survive.

One day, I woke up only find out that I’d become a Demon Lord, an individual responsible for protecting a dungeon. The world I’d been spirited away to was one filled with violence. Gigantic monsters wandered through it and competed with each other each and every day for the right to survive. I had no choice but to strengthen my dungeon’s defenses in hopes of living another day—or at least that was what I’d thought. For some odd reason, I instead ended up spending my days in relaxation and bliss.