One possible reason could be that his birth parents were in a difficult situation, like facing financial hardships or health problems. Another reason might be that they were in some kind of danger and couldn't take care of him, so they made the tough decision to give him up for adoption. It could also be that there was some sort of family secret or stigma associated with his birth that led to his adoption.
Well, in the fanfiction, his adoption could be due to the fact that his birth parents were part of a secret organization. Maybe they knew that their enemies would target their family, especially Ben. So, to protect him, they put him up for adoption. Or perhaps his parents were on some kind of mission and couldn't take a child with them. And they thought adoption would give Ben a better chance at a normal life.
Well, it can have a huge impact. For starters, he might feel a sense of abandonment, which could lead to him having trust issues. However, if he has a loving adoptive family, he could also grow up to be very confident. His adoption might also fuel his curiosity about his origins, which could be a driving force in his character. He might constantly strive to prove himself, either to his adoptive family or to himself, because of the insecurities related to his adoption. He could also be more open - minded to different cultures and ways of life, depending on the background of his adoptive family.
Maybe Ruby was born into a family that couldn't take care of her because of poverty. Her biological parents, despite loving her, had to give her up. She was then adopted by a family in Vale. This family could have been involved in the local Huntsman academy in some way, like supplying weapons or equipment. This exposure early on could have influenced Ruby's love for weapons and her dream to become a Huntress.
One reason could be that in the fanfiction, Ben is getting a lot of attention from other characters. Maybe the story has Ben in a romantic relationship with someone else, and Gwen, who has a close bond with Ben in the original series, feels left out. It could also be that the fanfiction portrays Ben in a heroic light without much focus on Gwen's role, making her jealous of the spotlight he's getting.
One possible reason could be a dark magic curse. In many fanfictions, an ancient or powerful dark magic spell might be placed on Harry, and despite all his skills and the help of his friends, he couldn't overcome it. This could be something that was secretly cast on him during his early years, perhaps related to his connection with Voldemort.
One reason could be a different family situation. For instance, if he was raised by someone other than the Dursleys, who might have been more involved in the dark arts. Another could be his experiences at Hogwarts. If he faced more discrimination or was wrongly accused often, it could lead to a sense of bitterness and a turn towards the dark side.
One possible plotline could be Naruto growing up with his uncle and learning different jutsu from him. His uncle might have a unique style of teaching that helps Naruto develop his skills faster. Maybe his uncle also has some secrets about Naruto's family that he gradually reveals as Naruto gets older.
One possible reason could be jealousy. Maybe his friends are jealous of Ash's success in his Pokemon journey. For example, if Ash wins a big tournament and gets all the fame, his friends might feel left out and betrayed. Another reason could be a misunderstanding. Ash might do something that his friends misinterpret. Say he makes a deal with an enemy in order to save his Pokemon, but his friends don't understand the situation and think he's turned on them.
Well, sometimes in fanfiction, the author wants to explore the theme of loneliness. So they create a scenario where Naruto's friends abandon him because they are influenced by the village's elders. The elders might spread false rumors about Naruto to maintain their control. His friends, being young and naive, believe these rumors and turn their backs on Naruto, which then leads to Naruto's journey of self - discovery and growth in solitude.
One possible reason could be that Naruto discovers some dark family secret that his parents want to keep hidden. For example, if there was a connection between the Uzumaki clan and some forbidden jutsu, and they fear Naruto might be exploited because of it. So they banish him to protect the clan's reputation and his own safety.
One possible reason could be that she is influenced by an enemy. Maybe the enemy has some sort of leverage over her or has brainwashed her into believing that Naruto is a threat. Another reason might be a misunderstanding. For example, she could misinterpret Naruto's actions as being unfaithful or harmful when in reality he has good intentions. It could also be due to her own insecurities. If she feels overshadowed by Naruto's popularity and power, she might betray him to assert her own identity.