Maybe it's a strange genetic experiment gone wrong. Some evil scientist in the fanfic world might have tampered with Naruto's DNA, adding some sort of aquatic - like genes that resulted in gills.
One idea could be Percy discovers he has a new ability related to his gills that allows him to communicate with underwater creatures in a more profound way. Maybe he can understand their ancient languages and has to use this new skill to solve an underwater mystery that threatens both the sea world and the surface world.
You can try fanfiction websites like Archive of Our Own (AO3) or FanFiction.net. AO3 has a wide range of Percy Jackson fanfics, and you can use the search function to specifically look for ones related to 'gills'. FanFiction.net also has a large collection, but the quality can vary more. Another option is to check out Percy Jackson - related forums where fans might recommend their favorite 'gills' fanfics.
😋The novel I recommend to you is Ballad of the Dividing Sea. It's a fantasy romance novel about a different continent. In the plot of the novel, the fragile ecosystem of the water world collapsed, causing the underwater world to become hell. The protagonist listened to the call of fate and looked back at himself. He became a mermaid who could live underwater after being modified and explored many mysterious underwater continents. I hope you like this fairy's recommendation. Muah ~😗
Well, having gills would obviously make him better at underwater activities. He could swim faster and stay underwater for longer periods, which could be useful in battles near water or in underwater missions.
I can't satisfy your needs. According to the information you provided, you are looking for a post-apocalyptic novel where the protagonist has the ability to evolve according to the environment, such as the ability to grow gills in the water. This type of novel is quite common, but it might not meet the recommendation criteria of mainstream novel websites because I can't recommend all novels. However, I can introduce you to some other types of novels, such as science fiction or horror novels. Perhaps you will like some of them.
Science fiction was a fictional genre that explored the possibilities of science, technology, and social change through imagination of the future. If you're interested in science fiction, I can introduce you to some classic works such as Galaxy Empire, Three-Body Problem, and Wandering Earth.
Horror novels were a type of novel that focused on horror and horror. They usually created a tense atmosphere by describing the terrifying experiences or scenes of the characters. If you're interested in horror novels, I can introduce you to some classic works such as Black Mirror, Horror Cruise, and The Sixth Sense.
I recommend an animated film called Finding Nemo to you. It tells the story of a future human and a group of fish. The protagonist, little Nimo, was caught in a human fish tank, and his father and many marine creatures began their journey to find him. In this futuristic world, humans invented a device called "fish gills" that allowed humans to breathe freely underwater. I hope you like this fairy's recommendation. Muah ~😗
"I recommend a science fiction novel to you. The title is called" Strange Stories of Murlocs ". When the male protagonist was young, he had fish gills installed on him so that he could breathe underwater due to a rare illness. When he grew up, he became a marine scientist. In an accident, he discovered a mysterious creature and fused with it by changing his genes, becoming a new creature in the ocean. He used his immortal body to explore more mysterious ocean worlds, and at the same time experienced many challenges and adventures. I hope you like my recommendation. Muah ~
"The Child of Reborn Technology" is a sci-fi novel written by the author, Chattering Fish. The general plot of this novel is:
Gao Tian was nominated as an academician of the Chinese Academy of Sciences at the age of 30. He was the youngest chief engineer of a project in the country. Due to external radiation, she suffered from a malignant brain tumor. When she was on her deathbed, she was filled with regret towards her parents. However, when he woke up, Gao Tian found that he had returned to his high school days, and his brain was a little different.
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"I'm a Salted Fish in a Wealthy Family" was a sci-fi space-time travel novel written by the author, Confessions of a Abandoned Otaku. The general plot of this novel was:
Yu Mu was a good-for-nothing, and her performance in the Energy Conversion Bureau was at the bottom every year. Then, he retired and entered a sadistic novel as a retirement. He just wanted to be a quiet passerby, but tell him why there was an antisocial demon king in the book. In order to escape, he could only escape with his life. In the end, the Demon King was furious. "I'll return the person to you, I'll return it to you." Yu Mu's backstage hurriedly said. Take it away, take it away."
Yu Mu: "Don't be agitated. I'll revive immediately." Don't be angry."
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'This Man Comes from the Deep Sea' was a sci-fi futuristic novel written by the author, Feng Qingyan.
His origins were mysterious, and his identity was a mystery!
The amnesiac brain was constantly awakening all kinds of black technology, and there were all kinds of secrets hidden in the body!
On this day, Harlow appeared on Earth's surface.
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"I Never Heard He's Super Rich" was a romantic youth-rebellious growth novel written by the author, Chili La. The general plot of this novel was:
It was clearly love at first sight, but they all thought that it was an uprising! This was a slightly hot-blooded and inspirational book, but it was actually very fresh and warm. The story began with a member of the active swimming team shamelessly staying at the house of a girl who specialized in marine life. They gradually developed feelings for each other over time. They helped each other and achieved each other's success. They found the positive energy to heal their inner wounds again and finally became the most suitable self for each other. The day he was banned, he seemed to have lost everything. She was walking aimlessly on the highway in a foreign country. Until the sun stubbornly pierced through the dark clouds, and half of the gray sky revealed a faint purple. He stood in the wind and raised his head. In his line of sight, the shadows of the trees danced and intertwined. A rainbow was hidden in the half-light, still shining brightly. After he won the gold medal that he had always dreamed of, a reporter openly asked him about the scandal between him and the granddaughter of the wood industry king. He took off his swimming goggles and rarely responded, but he did not answer the question. The reporter was dumbfounded. He wiped the water droplets off his face and explained,"That's why these creatures can easily fall into obstacles like the gillnet, because once they fall into it, it's hard to get out."
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"Farming and Raising Mermaids" was a sci-fi space-futuristic novel written by the author, Xu Zibai. QQ. The general plot of this novel was:
He didn't take it seriously even though he had obtained the Portable Space?
He sailed into the sea without anything in his space?
Do you think you're so awesome just because you're a science student? Do you think that the official crew members don't need money to eat too much?
Li Qinglan, a top student in the shipping department, accidentally obtained a farming space. Not long after, she accidentally joined the mysterious Sea Exploration Team space. A mermaid who did not eat fish appeared in the space. It was a life-saving skill in extremely dangerous waters! You dare not raise it?
What can I feed you…my mermaid…
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"My Past Life Exposed, Restarting the Age of Immortals" was a sci-fi futuristic novel written by the author, Durian Bomb Cat. The general plot of the novel was:
The Soul Ark was the latest black technology of the new era. It could use the information of the human soul to recall the memories of the other party's previous life. In order to raise money for his father's treatment, Shen Ye had participated in the program "Past and Present Life", which was a program that featured reincarnations of past lives. He laid down on the Soul Ark, and memories of his previous life flooded into his mind. In his first life, he wielded his sword and slashed out three thousand miles, opening the sky! Divine Destruction! In his second life, he floated in the sea of stars, annihilated his enemies in outer space, and died a lonely death. The third life…the reincarnation of nine lives. When Shen Ye's memories of his previous life were reactivated, the dusty era flowed again. The gods were revived, and the Age of Gods was restarted in the vast universe!
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The book "Doomsday Drifting Begins with the Construction of Ships" was a sci-fi novel about evolution and mutation written by the author, Don't Be Unhappy. The general plot of this novel was:
After waking up from his coma, Chen Xuan found himself floating on the sea. What was going on? The world had changed. Danger was everywhere. Creatures had mutated. There were strange fish that could not be caught, glowing seaweed, giant great white sharks, and mysterious monsters that could not be seen... and the first step to ensure survival was to build a small boat. If there was no food, they would fish. If there was no fresh water, he would just evaporate it. If he didn't have a weapon, he would make his own. If he didn't have any materials, he would just pick up the ocean trash. If they couldn't see land, they would farm on the boat. If you can't see hope, let me reignite it. The small boat was too small. His future goal was a huge ship. System + Drifting + Territory Construction + Survival + Farming, please take care of me.
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"Struggling in the Apocalyptic Insect Tide" was a sci-fi novel written by the author when he gave up. The general plot of this novel was:
After a heavy rain, the Earth's magnetic field was in chaos, and the national system was paralyzed. An inexplicable bug tide surged over and violently attacked the life on Earth.
Under wave after wave of insect attacks, the army suffered heavy casualties. The government was unable to deal with the affairs of the various regions. The world was in chaos from then on, and the various regions were governed!
During his escape, Lin Yu encountered a pool water that could strengthen his physique. In order to survive, he used the pool water to strengthen his body and build a survivor base, leading the base to struggle to survive in the fierce insect tide.
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It's Too Hard to Be a Salted Fish "was a sci-fi time-travel novel written by the author, Deep Sea Yuyu. The general plot of the novel was:
Gu Qian had accomplished nothing in his middle age. His wife had cheated on him, divorced him, and even took his son away. The drunk Gu Qian choked to death by the beads that fell from the sky. When he woke up again, he was already a teenager. His mind was getting clearer and clearer, his memory was getting more and more abnormal, and now that he had an alternate dimension full of treasures, wouldn't he become a CEO, marry a rich and beautiful woman, and reach the peak of his life? No! No! No! Gu Qian used the truth to tell you that a salted fish would not turn over just because he was reborn. Laziness was also cancer. There was no cure! However, God did not let Gu Qian get what he wanted…
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The book "The Mermaid Baby in the Galaxy" was a sci-fi space novel written by the author, Koi. The general plot of the novel was:
The new book,"Man in Space: The Country Has Allocated Me With a Partner", welcomed him into the pit!
Ling Xi was about to make her debut, but she discovered that she had become an egg and was carried away by someone! Ling Xi was so hungry inside the egg. It was not easy for her to break out of the shell. When she opened her eyes, she saw a handsome big brother watching her hatch…Baby Ling Xi: "Big brother ~"
Bai Xiu was expressionless.
――
"Uncle ~"
Bai Xiu said with a serious face,"Call me brother!"