One Piece theory claims Luffy’s devil fruit powers are something else entirely.

SUMMARY

The One Piece world has incorporated numerous such parts to the plot that are still considered mysteries today.

According to one notion, the power of the Five Elders stems from something other than the Devil Fruits.
The notion additionally proved that Zunesha heard something other than the liberation drums during the Onigashima War, and that Luffy isn’t actually Joyboy.

The One Piece world has introduced many such aspects in the story that to this day are considered a mystery. Be it the origin of Joyboy or the identity of Imu, One Piece mysteries have been developing for far too long and fans now only want to know the answers to these mysteries that have been unsolved for almost 30 years.
The Five Elders in One Piece
As the story of One Piece entered the final saga, fans expected that the series might start unraveling some mysteries that have been seen in the story and indeed that’s what Eiichiro Oda did. He started solving the mysteries, starting from the Five Elders. The recent chapters revealed the powers and abilities of the Gorosei.

However, according to one theory, the power of the Five Elders is not the result of the Devil Fruits, instead, it is something else entirely. This theory also proved that Luffy isn’t really Joyboy, and the drums of liberation that Zunesha heard during the Onigashima war were something else entirely.

One Piece Theory Claims The Five Elders Are Not Devil Fruit Users

While the powers of the Five Elders have been revealed in the recent chapters of the Egghead Island arc of One Piece, their origins, and the full extent have yet to be discussed in the story. The general idea among fans is that their powers are the result of mythical zoan Devil Fruits that are an extreme rarity in One Piece.

However, according to one theory posted by @GoochLord2217 on OPFanpage, the Five Elders are not Zoan Devil Fruit users, instead they are the devils who once killed take the form of Fruits and find another vessel to restart their lives. The form of the Five Elders that is shown during the Egghead arc is actually their true form.
Gorosei Devil Fruit forms
Since the Five Elders have never died, they have never taken another form and have been staying in the original form of the Gorosei since the beginning of the storyline of One Piece. The theory also claims that Joyboy was also not a Devil Fruit user but something similar to the Five Elders.

Theory Claims Zunesha Heard The Drums of Liberation For a Different Reason

According to the theory, just like the Five Elders, Joyboy was also not a Devil Fruit user but instead a creature who got killed by the Five Elders and later manifested as the Devil Fruit because the people got tired of suffering the wrath of the World Government and wished for his return so that he can save them.
Monkey D. Luffy transforming to Gear 5
This Devil Fruit which originally was Joyboy was eaten by Luffy, thus granting him the powers of Joyboy and helping him save the world from the torture of Imu, the Five Elders, and The World Government. The theory also claims that when Zunesha heard the Drums of Liberation, they were not from Luffy’s heartbeat but from the powers of the Joyboy Devil Fruit.

This Devil Fruit manifesting and being eaten by Luffy doesn’t really make him Joyboy. However, the theory doesn’t have any solid evidence and sounds too bizarre to be true. All of these mysteries are soon going to be discovered as the Egghead arc is going to end soon and One Piece is going to move on to the next phase of the Final Saga.