Weapons with Devil Fruits, despite being a bizarre concept, is one of the best ideas introduced to One Piece. Having a bizarre weapon-animal hybrid that can morph into strange shapes and attack enemies on its own is the perfect sort of combination of weird and awesome that One Piece thrives on. Sadly, so far in the series, although a handful of Devil Fruit-infused items exist in the story, only three weapons so far are enhanced with these amazing powers.