One Piece: The Return of All Things

Lin En, a new recruit at Marineford, is mediocre in talent and physique. After accidentally falling into the sea, he awakens an ability: seawater not only fails to drain his strength but activates 'The Return of All Things' for the first time—he touches the corpse of an executed pirate and copies the first Devil Fruit ability, 'Magnetism.' Starting as a sergeant, he participates in wiping out a pirate crew on a small island in the West Blue, gradually mastering a variant of the 'Six Powers' and fusing magnetism with physical techniques to develop 'Magnetic Storm Six Powers,' gaining some fame within the Marines. At the end of the volume, after openly defying a 'Buster Call' order to rescue a village slaughtered by pirates, he is demoted and transferred to the G-5 branch, thus leaving the core of the Marines but gaining greater freedom for development.