Warning: Mary Sue, Crack and shattering the dreams of anyone who believes in the myth of a Mizu Mizu no Mi.
Disclaimer: If I owned One Piece, this would have already happened in canon.
A young girl named Mary Sparkle Amethyst Ruby Sapphire Emerald Tiffany Gold D. Susan or Mary D. Sue for short, walked through the forest, sobbing to the animals about her tragic childhood.
Mary D. Sue had been beaten and abused all her life, never getting acknowledged by her adoptive parents…
And something about pirates and running away…. I don't know.
Anyway She walked through a forest on some island in the New World, hoping to find a way to escape her tragic life.
Suddenly she stumbled upon a clearing, complete with a half buried treasure chest.
Mary gasped and fell to her knees; surely this chest would contain something to end her suffering, right? She opened the chest and found an oddly shaped fruit, sort of like a giant raspberry but with each segment in the shape of a teardrop.
"Gasp!" Mary gasped; she had found a Devil Fruit! And judging by a book on Devil Fruits she had *conveniently* taken from her adopted parents' house it was the legendary Mizu Mizu no Mi; the most powerful fruit ever: the only one that could overcome the weakness of the ocean.
Making her decision, she picked up the fruit and took a large bite, feeling the power of the ocean flowing through her.
Her stomach churned, the feeling growing larger and resonating all through her body. She screamed Bloody Murder; it felt like her entire body was attempting to tear itself apart. Writhing in pain her body bulged in odd places until it finally just ripped itself apart and scattered into a million pieces.
Nearby an apple hanging on a tree changed form.
I can explain; basically I was thinking if Devil Fruits are repelled by water, wouldn't a fruit that turned you to water repel you? And since you're the water, your body is tearing itself apart trying to repel itself.