This anime has a complex magical system.
Here's a comprehensive guide to the magic of the anime, One Piece.
One Piece Magic Set 1 - Strawhats by kami-ranma on DeviantArt
Blackbeard: The One Piece Villain's Devil Fruit Powers & Origin
One Piece Finally Explains Luffy's New Devil Fruit Abilities
One Piece: Nico Robin's Devil Fruit Abilities, Explained
The New Power System in One Piece: Dark Magic & Demonic Devil
Donquixote Mjosgard 'One Piece': Saint Mjosgard, Explained
What is the devil fruit fish-fish fruit of Kaido in One Piece? How
One Piece Magic Set 5 - Swords by kami-ranma on DeviantArt
Jaygarcia Saturn, One Piece Wiki
One Piece Gear 5 explained: From Luffy's power to Tom and Jerry
Devil Fruits: Magic or Science? : r/OnePiece
The existence of Magic in One Piece : r/OnePiece
Magic Reveal Pads Bundle 1 piece (1 of the options below as
Soru Soru no Mi, One Piece Wiki