In the fanfiction, Naruto could have been possessed by some dark force. This dark - Naruto then starts to act in a very unpredictable and scary way, like randomly attacking people with great force. He might also have a really creepy look in his eyes, which scares everyone around him. The villagers who once knew Naruto as a friendly ninja would be shocked and terrified.
Perhaps in the fanfic, Izuku is possessed by some dark entity which changes his behavior and makes him do terrifying things, causing fear among his friends and foes alike. For example, his actions might be unpredictable and seem dangerous to those who know him. He could start speaking in strange voices or have sudden outbursts of strange powers that startle everyone. This would lead to a situation where everyone is scared of him, and the story could revolve around how he tries to get rid of this possession or control this new and scary side of himself.
One possible plot could be that Izuku has been through a really traumatic experience that has changed him. He starts to isolate himself and when people try to approach him, he acts in a way that scares them off. He could have developed some sort of survival - based aggression. For instance, if he was trapped in a really dangerous situation where he had to fight to survive, he might now react harshly to any sudden movements or people getting too close to him, which would scare his friends and classmates.
His close friends like Sasuke and Sakura would likely be among the most affected. They know Naruto well and seeing him in a terrifying state would be very shocking for them. For Sasuke, who has a deep bond with Naruto, it would be especially hard to face a scary Naruto.
His friends from U.A. High School such as Bakugo, Ochaco, and Iida would also likely be main characters. Since Izuku is scaring everyone, they would be the ones experiencing the fear and trying to figure out what has happened to him. Their reactions and attempts to deal with the situation would be important parts of the story.
His classmates like Bakugo could be a main character. Bakugo might be one of the first to notice the strange changes in Izuku and could be both scared and angry about it. He might try to confront Izuku, which could lead to some intense scenes.
In episode 134 of One Piece, Luffy's interest in books attracted everyone's attention because of a special book called the "Sea Tower Stone Book" that appeared in this episode. This book could absorb the essence of humans and have the power to make humans superhuman. When Luffy was reading this book, he was attracted by the power in the book and tried to find more books to understand this power.
Luffy was interested in books because he was eager to learn more about the sea and marine life and hoped to become a great navigator. He hoped to improve his wisdom and ability to better explore the sea and the world by reading the stone book.
The Shining was a classic horror film directed by Stanley Kubrick and released in 1980. The movie was about a lonely hotel owner and his family staying in a seemingly comfortable but actually extremely scary room. As time passed, they began to find themselves trapped in a mysterious and terrifying world.
The film received high praise and reputation around the world and was considered a classic in the history of film. The horror atmosphere and the design of the thrilling scenes were widely imitated and used as a representative work in the history of movies.
You could try some popular fanfic websites like FanFiction.net or Archive of Our Own. They usually have a wide range of One Piece fanfics, so there's a chance you'll find this one there.
I'm not sure about this particular 'everyone watch luffy memories fanfic'. However, in a fanfic like this, it might show Luffy's memories of key battles. For example, his fight against Arlong which was very important for him to protect his friends in the village. It might also include his memories of when he first set out to sea, full of dreams and naivete.