For the most part, these Devil Fruits forever changed the story based on their usage, such as being used to kill their victims or affecting how society functions on certain islands of the Grand Line.

This is where Chopper's Hito Hito no Mi comes in, as it may hold the crown for the worst Devil Fruit in the entire One Piece series, simply because it grants the user the intelligence of a human.

Devil fruit users are considered creatures that defy the law of nature and disrupt the balance of the world. Therefore, the mother of natural elements, i.e. the sea, rejects them completely.