One Piece can be divided into three series:
One: Superman Department
Features: Super shemale fruit can manipulate specific substances, or make specific changes in the body, or launch physical attacks and so on. Like luffy.
Two: animal system
Features: the monster fruit can strengthen the body of the able person, improve the speed and attack power, and is the strongest aid in hand-to-hand combat. Qiao Ba, for example.
III: Ministry of Nature
Features: Natural demon fruit can make the body elemental and make physical attacks ineffective. Like ace.
Illustrate the fruits of three demons:
Left: Superman Department
Middle: Ministry of Nature
Right: Fauna.