One Piece : Marine Scientist

Leon Reincarnated into the world of One Piece and unexpectedly became Kizaru younger brother—an eight-year-old brat!



What could an eight-year-old brat possibly do?



Just laze around under the protection of an admiral, right?



But then, a high-tech system activated, gifting him the pinnacle of One Piece technology—the Seraphim!



With nothing better to do, he tinkered around, never expecting it would cause a sensation…



From Seraphim at the level of the Warlords, all the way up to Admiral-tier and even Yonko-tier Seraphim.



This directly provided the Marines with unprecedented, overwhelming support—while completely overturning the balance of the One Piece world!