One Piece: The user of the Nen-Nen Fruit, who overturned the sea.

[Pirate faction] [Slow burn] [Gradual growth] [User of the Nen-Nen Fruit] [Great swordsman] [Powerful user of all three types of Haki] [The Float-Float Fruit is fake] [No female lead]
Feed, feed, feed!
Golden Lion: Roy, why isn't my Float-Float Fruit as strong as your Mind-Mind Fruit?
Roy: How should I know?!
Barrett, Mihawk, Tezzo, Crocodile...
Hurry up and get on the ship.
Roy arrives in the world of One Piece and discovers that the future powerhouses are still young.
They lured them all onto their own boat, one by one.
When Luffy set sail, Roy looked back and exclaimed, "Oh no! I've become the world's ruler!"
When Luffy arrived in the New World, Roy looked back at his team and said, "Brothers, you guys go first. I'll see what this guy is all about."