Despite being the primary power system of One Piece, at times it doesn’t feel like every aspect of the mysterious abilities is explored in a substantial way. Namely, the weaknesses of the system, the fact that Devil Fruit users are cursed by the sea and drained by its energy, aren’t brought up nearly as much. This is especially true with the modern introduction of Haki, which at times, completely overshadows some aspects of Devil Fruits in One Piece.